9/15/2025 Air Quality Forecast

FORECAST SUMMARY: Monday, September 15, 2025, through Friday, September 19, 2025

 OZONE: 8-hour average Ozone concentrations are expected to be mostly Good (AQI Green) to Low Moderate (AQI Yellow).  There is a slight chance of isolated USG (AQI Orange).

 PM-2.5: 24-hour average Fine Particulate concentrations are expected to be Good (AQI Green) to Moderate (AQI Yellow).

  FORECAST DISCUSSION

 The last full week of summer will feature summer-like weather with temperatures reaching the mid to upper 80’s with low humidity and clear skies.  Ideal weather to be outside before the cooler weather of Fall arrives.

 This time of year usually produces Good Air Quality.  Wildfire smoke is currently contained to the northern provinces of Canada is not presenting a problem.  Ozone production is still possible, as we saw a few scattered, single monitor Low USG readings, last week.  However, since the days are getting shorter and the nights are getting cooler, no widespread USG conditions are expected.  It is possible that an isolated monitor could reach Low USG, however.

 The 7-day forecast has the current weather pattern remaining in place.  With no turnover in air mass we can expect fine particulates to accumulate but no worse than the Moderate levels of the AQI are expected.  As mentioned above, ozone production could yield some isolated Low USG readings, but widespread Moderate readings are more likely.

  EXTENDED FORECAST:

 Air Quality is expected to remain Good to Moderate entering the upcoming weekend.

9/12/2025 Air Quality Forecast

FORECAST SUMMARY: Friday, September 12, 2025, through Monday, September 15, 2025

Ozone:

Ozone concentrations are expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

FORECAST DISCUSSION:

Fair weather clouds, mostly sunny skies and surface temperatures reaching the 80s is what Michiganders have in store for this Friday. High-pressure sits both to our northeast and southeast, providing warm and sunny conditions. The only real hindrance in the upcoming forecast is tomorrow, Saturday, with scattered to spotty showers possible for southern Michigan as a weak frontal boundary approaches the state, it will not be a complete washout, however. Surface temperatures will range in the mid-70s for the majority of the state, with overcast to partly cloudy skies throughout the day. Come Sunday, although, we are back under High-pressure with clearing skies and making a run at 80-degree temperatures across the state. Monday and into next week, this trend continues as warmer temperatures return to the Great Lakes.

For air quality, with surface temperatures reaching the 80s, coupled with light winds, Ozone may pose a threat with concentrations reaching the high-Moderate range in both southwest and southeast Michigan, with the possibility of an hourly concentration in the Unhealthy for Sensitive Groups (USG) range. These concentrations in the USG range should not be widespread, however. It is not uncommon for USG-level Ozone concentrations in the month of September, but decreasing sunlight and an unfavorable sun angle, makes it hard for Ozone to produce. With even warmer temperatures next week, Ozone will be looked at more closely. PM-2.5 concentrations will continue their trend of Good to Moderate concentrations, especially for more populated areas like Grand Rapids and Detroit. Southerly flow later this weekend may increase concentrations into the mid-Moderate range, but only for a few hours before decreasing.

EXTENDED FORECAST:

Summer-like temperatures return next week as the mid-to-upper 80s are on the horizon for areas across Michigan. Air quality, as of now, will remain in the Good to Moderate range.

Next Forecast update: Monday, September 15, 2025

9/05/2025 Air Quality Forecast

FORECAST SUMMARY: Friday September 5th, 2025, through Monday September 8th, 2025

Ozone:

Ozone concentrations are expected to be in the Good (Green AQI) range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

FORECAST DISCUSSION:

A breezy Friday morning and afternoon will kick off the first weekend of September with surface temperatures ranging from the upper-50s to mid-60s throughout the weekend. A Low-pressure system started to traverse across the Great Lakes region early Friday morning and is the reasoning behind the breezy conditions. The gradient of pressure within the atmosphere as the Low-pressure moves through is being compressed, which in turn produces windy conditions with the possibility of strong gusts. After all, wind speed and gusts are directly correlated with how tight the pressure gradient is within the atmosphere.

Going into Saturday, winds will continue to slow down as the aforementioned Low-pressure moves further east, and the skies will open up to more sunshine. Even though it is not astronomical Fall, it is technically meteorological Fall, and it very much will feel like Fall Saturday and into Sunday with highs in the mid-60s at best. Sunday will essentially be a copy and paste of Saturday with light to moderate winds. Due to the cooler temperatures and wind direction being predominantly west-northwesterly, lake-effect pop-up rain showers should be expected throughout the weekend as well. Just like lake-effect snow, the lake waters are warmer than the surrounding air, so the same mechanism of lake-effect snow takes place, but in this case, the surface air is still in the 50s and 60s, so precipitation will fall in the form of rain. As said above though, these will be sporadic and should not last long.

For air quality, the cooler temperatures will continue to keep Ozone concentrations at bay as we are closing in on the end of the Ozone season. For PM-2.5, a small and rather light plume of smoke is currently in the Midwest this Friday morning as monitors across the region are reading in the Moderate range. With the windy conditions in place, this plume will move out rather quickly. Throughout the rest of the weekend, however, Good PM-2.5 concentrations are expected with the exception of early morning light winds allowing for particulate build up in the more populated areas of metro Detroit and Grand Rapids.

EXTENDED FORECAST:

Temperatures return to the 70s next week with a small possibility of some wildfire smoke returning, but nothing more than Moderate concentrations as of right now. Air quality will be in the Good to Moderate range.

Next Forecast update: Monday September 8th, 2025

9/02/2025 Air Quality Forecast

FORECAST SUMMARY: Tuesday September 2nd, 2025, through Friday September 5th, 2025

Ozone:

Ozone concentrations are expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

FORECAST DISCUSSION:

We enter the first full week of September with the official start of Meteorological Fall passing on September 1st, providing near-normal temperatures today, Tuesday, and a cool down later this week.

Tuesday will be an extension of the beautiful weather we had over the holiday weekend with temperatures in the 70s and ample sunlight. This is due to a High-pressure system sitting just to our southwest funneling in clear skies and warm air. Come midweek, however, this pattern will give way to a Low-pressure system and associated cold front that will cool us down into the 60s for southern Michigan and the 50s for the upper peninsula. With this cold front, rain showers are expected Wednesday morning through early Thursday afternoon as the cold front traverses through the state from the northwest to the southeast. On the backside of the cold front, will be a High-pressure system replacing the mid-to-late week weather regime, which will provide sunny conditions, albeit cooler. It will truly feel like Fall this upcoming weekend with temperatures ranging from the 50s to the mid-60s.

For air quality, with the cooler temperatures in place, along with shifting weather patterns, Ozone will continue to be a non-issue as the photochemical reaction that takes place to form Ozone will not have the proper ingredients to initiate. For PM-2.5, a few long-term smoke models are showing some amounts of wildfire smoke making its way down into the Midwest later this week and into the weekend. Nothing more than the Moderate range in terms of concentrations, as of now, are expected. So, in all, air quality is expected to range in the Good to Moderate range for the remainder of this week.

EXTENDED FORECAST:

As mentioned above, Fall-like weather is expected for the first full weekend of September with air quality remaining in the Good to Moderate range.

Next Forecast update: Friday September 5th, 2025

8/29/2025 Air Quality Forecast

FORECAST SUMMARY: Friday, August 29, 2025, through Tuesday, September 2, 2025

OZONE: 8-hour average Ozone concentrations are expected to be mostly Good (AQI Green).

PM-2.5: 24-hour average Fine Particulate concentrations are also expected to be mostly Good (AQI Green) to scattered Low Moderate (AQI Yellow).

  FORECAST DISCUSSION

Cooler than normal weather will continue into the holiday weekend but will gradually climb back to the normal range of around 80 degrees by Monday.  Night temperatures will continue to run below normal for chilly evenings.  Clear skies make for warming during the day but quickly lose that heat, at night, without the cloud cover.  This cool, dry weather trend is due to a surface high pressure cell building over the central Great Lakes. 

The cool, dry weather should persist through the Labor Day weekend and into early next week with the next chance of rain coming during Wednesday.

These factors will lead to continued Good Air Quality with the possibility of scattered Low Moderate developing in Southeast Michigan by the end of the forecast period.

  EXTENDED FORECAST:

 Air Quality is expected to remain Good to Low Moderate entering the next work week.

8/25/2025 Air Quality Forecast

FORECAST SUMMARY: Monday, August 25, 2025, through Friday, August 29, 2025

OZONE: 8-hour average Ozone concentrations are expected to be mostly Good (AQI Green).

PM-2.5: 24-hour average Fine Particulate concentrations are also expected to be mostly Good (AQI Green).

FORECAST DISCUSSION

It has been a while since I have been able to write a forecast predicting Good AQI’s for a whole work week.  That is quite a treat from the past three months where we were on the edge of our seats watching Canadian wildfire smoke drift our direction. 

It has been a summer for poor Air Quality thanks to unprecedented Canadian wildfires.  While the number of 2025 Canadian wildfires have been roughly average, the size of the area burned has been twice the size of an average summer.  Many of those fires are further east than the typical Canadian fires we normally see in the more western provinces.  The closer the fires, the more likely thick smoke will reach the Midwest. 

The good news is that recent rains, through much of Canada, have reduced the area susceptible to new fire.  And it has helped knock down much of the smoke from existing fires which should be starting to burn out with the approach of cooler weather.  A check of the AirNow.gov maps shows the vast majority of the United States and Canada currently under Good AQI. 

Weatherwise, this week will continue to be a preview of Fall conditions.  A cooling trend will continue as a low-pressure trough slides eastward that will likely kick off a few light lake effect showers, mostly across northern lower and closer the Lake Michigan shoreline.  A high-pressure cell will work its way through the Ohio Valley to central Appalachia, Tuesday night and Wednesday, resulting in dryer weather for the second half of the week.  Even as westerly winds draw in a slightly warmer air, I am not expecting to see the thermometer break the 80-degree mark until perhaps Labor Day.  Nights will be noticeably chillier with temperatures dropping into the high 40’s on some nights.  So, ozone development is not expected to be an issue, either. 

EXTENDED FORECAST:

 Air Quality is expected to remain mostly Good for the holiday weekend. 

8/22/2025 Air Quality Forecast

FORECAST SUMMARY: Friday, August 22, 2025 - Monday, August 25, 2025

Ozone: 8-hour ozone concentrations are expected to range mostly Good (Green AQI) with a few Moderate (Yellow AQI) concentrations possible south on Friday and Saturday.

PM-2.5: 24-hour daily average Fine Particulate concentrations will average Good with a few low Moderates Friday and Saturday.

FORECAST DISCUSSION:

This weekend Michigan will experience fall-like conditions for the first time this season. The cool down happens as cold air filters in behind a cold front tracking northwest to southeast today, Friday, through Saturday. Precipitation also moves in, starting in the upper peninsula Friday and continuing into the lower peninsula Saturday. High temperatures on Friday will range from the 70s in the north to the 80s in the south. By Sunday, high temperatures will struggle to reach the 60s in the upper peninsula and the low to mid 70s in the south. Low temperatures will fall into the 40s later in the forecast period. Temperatures on Sunday will be cold enough for lake effect precipitation to develop due to the cold northwesterly flow over the warmer lake water.

For air quality, mostly Good levels of both ozone and fine particulate can be expected this forecast period. The only chance for low Moderate concentrations for either pollutant would be Friday or Saturday in southern locations. Earlier this summer northwest winds have brought increased PM2.5 concentrations due to the Canadian wildfires. We did evaluate current smoke conditions, and while the Canadian fires persist, the fire intensities are currently low, and they are not generating much smoke. Because of this, we do not expect an increase in PM2.5 concentrations this forecast period.

EXTENDED FORECAST:

Cool Canadian air lingers into the new workweek, and we expect Good air quality levels during this period.

Next Forecast update: Monday, August 25, 2025

8/18/2025 Air Quality Forecast

FORECAST SUMMARY: Monday, August 18, 2025 - Friday, August 22, 2025

Ozone: 8-hour ozone concentrations are expected to range mostly Good (Green AQI) with only a few Moderate (Yellow AQI) concentrations possible south.

PM-2.5: 24-hour daily average Fine Particulate concentrations will average upper Good to middle Moderate.

 FORECAST DISCUSSION:

Two weather systems bring showers and storms into the forecast this week. The first one moves west to east through the region Monday into Tuesday, with the second one moving in Friday into early Saturday. Conditions dry out in the wake of each system as high pressure builds in; less humidity and more comfortable temperatures can be expected as well. High temperatures during the workweek will range from around 70 in the north to around 80 in the south. By the weekend, high temperatures fall to the 60s in the north and 70s in the south.

We expect ozone concentrations this week to range mostly Good thanks to the cooler surface and upper-level temperatures, along with clouds associated with the systems moving through. Northwesterly winds this summer have brought down smoke from Canadian wildfires; however, fire intensities and fire hotspots have improved over the last week or two. These improvements have helped decrease smoke production and therefore have reduced the threat of smoke moving into our region. Based on current smoke and forecast models, we do not anticipate PM2.5 to reach higher than the middle Moderate range. We will continue to evaluate updated smoke and forecast models as the week progresses, and this forecast will be updated if we expect PM2.5 concentrations to reach higher than what is currently forecast.

EXTENDED FORECAST:

Cool Canadian air sinks into the region behind the Friday/Saturday front. At this time, smoke moving in behind the boundary is not a concern; however, we will be tracking smoke models as the week progresses. Air quality late in the forecast period should be no higher than Moderate.

Next Forecast update: Friday, August 22, 2025

8/15/2025 Air Quality Forecast

FORECAST SUMMARY: Friday August 15, 2025, through Monday August 18, 2025

Ozone:

Ozone concentrations are expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Moderate (Yellow AQI) range.

FORECAST DISCUSSION:

We incredulously enter mid-August this upcoming weekend with summer-like temperatures continuing in the lower peninsula and cooler temperatures in the upper peninsula. Surface high temperatures are expected to be in the mid-to-upper 80s for the lower peninsula with high dewpoints expected throughout southern Michigan. For the upper peninsula, a weak pressure system and frontal boundary will linger in the Northwoods this weekend to produce northerly flow, which in turn, will keep northern areas cooler and slightly drier.

With the majority of the southern Great Lakes dealing with high dewpoints and humidity, pop up showers should be expected throughout this weekend along with the possibility of a few lines of rain and potential storms. As of now, the areas with the greatest chance of precipitation will be western and northern areas. This weekend will not be a complete wash out, as some models are showing rain dissipating earlier than others, but some areas across Michigan will see precipitation.

For air quality, region-wide Moderate PM-2.5 concentrations are being reported currently with those concentrations expected to persist throughout the weekend. Relatively light winds will lessen the dispersion capability of these concentrations which is why they are expected to linger. For Ozone, a few of the ingredients for Ozone development will be present this weekend, but cloudy conditions and high dewpoints will help keep Ozone at bay. We have seen historically when dewpoints reach the upper-60s and into the low-70s, the Ozone chemical reaction does not react well within the atmosphere. One thought is that the air is too heavy and moist for the precursors to react with residual Oxygen atoms. Another is that there is too much moisture in the air so the UV radiation coming in is being scattered and refracted by the water droplets in the air, so the reaction to produce Ozone does not occur effectively. Due to these conditions in place this weekend, mid to potentially high Moderate Ozone concentrations are expected.

EXTENDED FORECAST:

The airmass this weekend continues into late Sunday with a cooldown expected early to mid-next week. Air quality is expected to range between the Good and Moderate range.

Next Forecast update: Monday August 18, 2025

8/12/2025 Air Quality Forecast

FORECAST SUMMARY: Tuesday August 12, 2025, through Friday August 15, 2025

Ozone:

Ozone concentrations are expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Moderate (yellow AQI) range with potential hourly concentrations in the Unhealthy for Sensitive Groups (Orange AQI) range.

Air Quality Advisory for the Upper Peninsula until noon on Tuesday, August 12th

 The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has issued an Air Quality Advisory for elevated levels of fine particulate (PM2.5) across the Upper Peninsula of Michigan. Pollutants within those areas are expected to be in the Unhealthy for Sensitive Groups (USG, Orange AQI) range.

The Air Quality Advisory includes the following counties:

Alger, Baraga, Chippewa, Delta, Dickinson, Gogebic, Houghton, Iron, Keweenaw, Luce, Mackinac, Marquette, Menominee, Ontonagon, Schoolcraft

FORECAST DISCUSSION:

Currently, there is an Air Quality Advisory in place for the Upper Peninsula which will be expiring at noon today, Tuesday August 12th. Most recent smoke models are showing the plume becoming less and less intense as we get into Tuesday afternoon and evening. Now, there may be a possibility of hourly USG (Orange AQI) concentrations, but overall concentrations are expected to remain in the mid-to-high Moderate (Yellow AQI) range.

Later this evening and into overnight, a cold front will cross over the Great Lake region, providing a good chance at rain showers across Michigan. This cold front will also shift winds to a more northerly direction, initially northwesterly, before turning to a more northeasterly direction on Thursday. With the shift in winds, our eyes will be watching for any more smoke intrusions later this week, but as of now, smoke, and associated PM-2.5 concentrations look to remain in the Moderate (Yellow AQI) range through the remainder of this week.

For Ozone, after today, as mentioned above, winds shift to an unfavorable direction for Ozone development for the remainder of the work week, so Ozone does not pose a real threat for the next couple of days. Today may see an increase into the high-Moderate (Yellow AQI) range, but with chances of rain and northerly winds this week, Ozone will remain in the Good to Moderate range.

Surface temperature-wise, we still hang around the 80s for the majority of Michigan with ample sunlight with the exception of later Tuesday and early Wednesday. A weaker cold front looks to impact us on Thursday, but a slight change of wind direction looks to be the only impact, with little to no chance of rain expected. Air and dewpoint temperatures look to climb as we approach the end of this week with the weekend ahead looking to be similar to last weekend: hot and muggy.

EXTENDED FORECAST:

A similar set up compared to last weekend is expected to occur this upcoming weekend with heat and humidity returning. Air quality is expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

Next Forecast update: Friday August 15, 2025

8/11/2025 Air Quality Forecast

FORECAST SUMMARY: Monday August 11, 2025, through Tuesday August 12, 2025

Ozone:

Ozone concentrations are expected to be in the Good (Green AQI) to Moderate (Yellow AQI) range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Unhealthy for Sensitive Groups (Orange AQI) range.

 Air Quality Advisory for the Upper Peninsula on Monday, August 11th until noon on Tuesday, August 12th

 The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has issued an Air Quality Advisory for elevated levels of fine particulate (PM2.5) across the Upper Peninsula of Michigan. Pollutants within those areas are expected to be in the Unhealthy for Sensitive Groups (USG, Orange AQI) range.

 The Air Quality Advisory includes the following counties:

 Alger, Baraga, Chippewa, Delta, Dickinson, Gogebic, Houghton, Iron, Keweenaw, Luce, Mackinac, Marquette, Menominee, Ontonagon, Schoolcraft

 FORECAST DISCUSSION:

We start off this new work week with surface temperatures expected to range from the upper-70s to upper-80s with relatively high dewpoint temperatures as well. A predominantly southwest wind will keep temperatures high Monday afternoon and into Tuesday with rain chances increasing we go into Monday afternoon and evening. Rain chances remain on Tuesday as well, with the capability of storms producing.

There is currently an Air Quality Advisory in place for the Upper Peninsula today, through noon on Tuesday. Wildfire smoke from Canadian fires is expected to move through the upper Great Lakes today and tomorrow, Tuesday. After this initial plume moves through, a potential additional plume may cross over the same areas into Wednesday due to a cold front moving through the region. If there needs to be an extension of the Advisory, it will be made on Tuesday morning when this forecast is updated.

Ozone development will be watched this afternoon and into Tuesday as favorable conditions exist for Ozone to produce over west and southwest Michigan. However, high dewpoint temperatures and the potential of rain showers are currently looking to keep Ozone development at bay. Mid-to-high Moderate concentrations are expected with the possibility of hourly Unhealthy for Sensitive Groups concentrations in southwest Michigan. As of now, the 8-hour Ozone average is expected to remain in the Moderate range.

EXTENDED FORECAST:

A slight cool down is expected mid-to-late week after a cold front moves through and drops surface high temperatures into the low-80s. This is short-lived as hot temperatures return for the weekend ahead, along with high dewpoints. Ozone and PM-2.5 concentrations will be monitored throughout the week.

Next Forecast update: Tuesday August 12, 2025

8/10/2025 Air Quality Forecast

FORECAST SUMMARY: Sunday, August 10, 2025 - Monday, August 11, 2025

Ozone: 8-hour ozone concentrations are expected to range between Good (Green AQI) and Moderate (Yellow AQI).

PM-2.5: 24-hour daily average Fine Particulate concentrations will average mostly Moderate with Unhealthy for Sensitive Groups (USG, Orange AQI) range possible in the Upper Peninsula on Monday.

 Air Quality Advisory for the Upper Peninsula on Monday, August 11th until noon on Tuesday, August 12th

 The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has issued an Air Quality Advisory for elevated levels of fine particulate (PM2.5) across the Upper Peninsula of Michigan. Pollutants within those areas are expected to be in the Unhealthy for Sensitive Groups (USG, Orange AQI) range.

 The Air Quality Advisory includes the following counties:

 Alger, Baraga, Chippewa, Delta, Dickinson, Gogebic, Houghton, Iron, Keweenaw, Luce, Mackinac, Marquette, Menominee, Ontonagon, Schoolcraft

FORECAST DISCUSSION:

This forecast update is warranted due to wildfire smoke entering the Upper Peninsula of Michigan starting Monday morning. This is happening as a low-pressure area to our north across Ontario moves northeast, bringing a cold front towards the Great Lakes region. Hourly levels of PM2.5 on Sunday morning were in the USG to Unhealthy range across the Dakotas as northerly winds behind the boundary pulled smoke plumes south.

 As the front tracks east Sunday into Monday, the smoke plume moves east as well. Wildfire smoke is expected to enter the western Upper Peninsula early Monday, pushing east through the day. At this point it looks like smoke should stay north and west of the Lower Peninsula; however, current weather and smoke models will be evaluated Monday morning to determine if the air quality advisory will need to be expanded into other parts of the state. Levels of PM2.5 in the USG range are likely Monday across the Upper Peninsula with some locations reaching the Unhealthy (Red, AQI) range for a few hours. Levels across the rest of the state will range mostly Moderate.

 Muggy conditions and clouds associated with storm chances will keep ozone from reaching higher than Moderate Sunday or Monday.

 EXTENDED FORECAST:

Smoke could linger on Tuesday along with chances for precipitation. High pressure then moves in past mid-week.

Next Forecast update: Monday, August 11, 2025

8/7/2025 Air Quality Forecast

Air Quality Forecast: Thursday, August 7 – Friday, August 8, 2025

Ozone:
8-hour average ozone concentrations are expected to range from Good (Green AQI) to High Moderate (Yellow AQI), with the potential for scattered Unhealthy for Sensitive Groups (USG, Orange AQI).

PM-2.5:
Fine particulate (PM-2.5) concentrations are expected to remain mostly Moderate (Yellow AQI).

Summary:
Air quality continues to improve compared to the previous week. Most areas reported Moderate AQI on Wednesday, with the only USG readings occurring in the Upper Peninsula. Easterly and southerly winds are helping to keep wildfire smoke and ozone precursors out of the region, though hazy conditions may linger due to high humidity and residual particulates.

Ozone levels are expected to remain mostly moderate, though some scattered USG levels are possible Thursday. Cloud cover and scattered showers on Friday should limit additional ozone buildup.

While the worst of the smoke has moved on, wildfires in Canada continue. Forecasts suggest continued southerly winds, which should help keep most smoke north of the state in the coming days.

Next forecast update expected Friday morning.

8/6/2025 Air Quality Forecast

OZONE: 8-hour average Ozone concentrations are expected to range between Good (AQI Green) and High Moderate (AQI Yellow).

PM-2.5: 24-hour average Fine Particulate concentrations are expected to be mostly High Moderate (AQI Yellow) with scattered Unhealthy for Sensitive Groups (USG) (AQI Orange), especially in the Northern Lower Peninsula and Upper Peninsula.

FORECAST DISCUSSION

As I checked the current Wednesday morning monitor readings I was relieved to see more Moderate readings than USG or Unhealthy.  It has been over a week since that has occurred, and those monitors are continuing to trend downward!  Yes, when you looked outside, this morning, you were still seeing hazy conditions.  Although trending downward, the current High Moderate concentrations will not give us the bright blue skies we have been seeking.  Fortunately, much of this morning’s haze comes from high humidity and good, old fashion fog.  That fog should burn off and some haze will persist, but it should not be as bad as what we have been experiencing for well over a week.  As a result, all current Air Quality Advisories for smoke will be discontinued beginning Thursday, although High Moderate conditions are likely to persist.

The air quality smoke models indicate that this improvement trend should continue.  The long-range smoke models have a bit of elevated smoke touching the western U.P. during Monday but that remains to be seen. 

The southerly winds we are expecting beginning Thursday should keep the Canadian smoke at bay, but it will bring heat and humidity for the foreseeable future.  As mentioned in previous forecasts, elevated ozone could be our next challenge.  A review of yesterday’s Midwest monitor summary showed some elevated ozone around Chicago and Milwaukee.  The easterly winds that are pushing the smoke out of Michigan are also keeping most of the ozone producing chemicals on their side of the lake.  Since it is hard to predict if enough leftover smoke residue is around Michigan to produce ozone, plus southerly winds bringing heat, humidity, and potentially dirtier air from down south, we will update this forecast Thursday morning.

EXTENDED FORECAST:

Air Quality remains in question while some leftover smoke residue remains in the air and ozone levels may increase.

08/04/2025 Forecast Update

Monday, August 4, 2025 – Tuesday, August 5, 2025

Ozone

Ozone concentrations will range from Good (Green AQI) to Moderate (Yellow AQI).

PM-2.5

Fine particulate levels will be mostly Unhealthy for Sensitive Groups (USG, Orange AQI), with brief periods of Unhealthy (Red AQI) possible.

Forecast Discussion

Wildfire smoke from Canada and a persistent high-pressure system continue to trap haze across Michigan. Most monitors are reporting USG (Orange AQI), with some hitting Unhealthy (Red AQI) levels.

Conditions are expected to stay hazy through Tuesday. Improvements may come mid-week as the high-pressure system moves out, but forecasts will be updated as needed.

Ozone could rise later this week, especially with warmer temperatures and lingering pollutants.

Extended Forecast

Air quality will remain dependent on smoke movement and possible ozone increases later in the week.

08/02/2025 Forecast Update

Ozone:
Ozone concentrations are expected to range between Good (Green AQI) and Moderate (Yellow AQI).

PM-2.5 (Fine Particulate):
PM-2.5 concentrations are expected to remain in the Unhealthy for Sensitive Groups (USG, Orange AQI) range, with some areas reaching Unhealthy (Red AQI) levels.

Forecast Discussion:
After a brief improvement in air quality across the Lower Peninsula on Friday, wildfire smoke is expected to return as winds shift back to a northwesterly flow. The Upper Peninsula experienced USG concentrations Friday, with only a short period of relief in the eastern regions.

Today (Saturday) and tomorrow (Sunday), smoke plumes will move southward, impacting the entire state once again. Elevated PM2.5 levels are anticipated across Michigan through the weekend.

Ozone levels are projected to stay within the Good to Moderate range for now. However, as this smoke episode comes to an end early next week, conditions will be monitored closely. Historically, lingering smoke can enhance ozone formation. If ozone concentrations appear likely to exceed USG levels, they will be incorporated into the ongoing forecast updates.

Extended Forecast:
Wildfire smoke and elevated PM2.5 concentrations are expected to persist through the weekend. Forecast updates will continue daily until this smoke event concludes.

07/31/2025 Forecast Update

Thursday, July 31, 2025 – Friday, August 1, 2025

Ozone:
8-hour ozone concentrations are expected to range between Good (Green AQI) and Moderate (Yellow AQI).

PM-2.5 (Fine Particulate):
24-hour daily average concentrations will mostly remain in the Unhealthy for Sensitive Groups (USG, Orange AQI) range, with Unhealthy (Red AQI) concentrations possible in some areas.

Air Quality Advisory: Thursday through Saturday
The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has issued an Air Quality Advisory for elevated levels of fine particulate (PM2.5) across all Michigan counties. PM2.5 concentrations are expected to remain in the USG (Orange AQI) range, with some locations reaching the Unhealthy (Red AQI) range through Saturday.

Forecast Discussion:
Smoke from Canadian wildfires will persist over Michigan on Thursday, keeping PM2.5 levels elevated. While some improvement in air quality is possible in the Lower Peninsula late Thursday into Friday, conditions are expected to worsen again as additional smoke moves into the region. High pressure overhead will limit smoke dispersion, maintaining USG-level pollution and increasing the chance of localized Unhealthy readings through Saturday.

Ozone levels are expected to stay within the Moderate range due to cooler temperatures; however, the presence of surface smoke could cause unexpected increases. Ozone forecasts will be closely monitored through the weekend.

Extended Forecast:
Comfortable weather with sunshine is expected in the extended forecast. We will continue to monitor smoke impacts and adjust pollution forecasts as needed.

Next Forecast Update:
Friday, August 1, 2025

07/30/2025 Forecast Update

Pollutant Overview

Ozone Forecast:

8-hour ozone concentrations are expected to range between Good (Green AQI) and Moderate (Yellow AQI). Cloud cover and cooler air will help limit ozone levels, though smoke may cause localized increases.

PM-2.5 Forecast (Fine Particulates):

24-hour average PM-2.5 concentrations will increase into the Unhealthy for Sensitive Groups (USG, Orange AQI) range across Michigan. Some locations, especially in northern areas, may see Unhealthy (Red AQI) levels as smoke from Canadian wildfires moves through the state.

Air Quality Advisory:

An Air Quality Advisory is in effect for all Michigan counties on Wednesday and Thursday due to elevated levels of fine particulate (PM2.5). This will be re-evaluated Thursday morning to determine if an extension is needed.

Forecast Discussion:

Smoke from Canadian wildfires entered northern Michigan Tuesday and will continue spreading southward through Thursday. A cold front will aid in pulling this smoke further into the state. High pressure settling in behind the front will bring north to northeast winds, continuing the influx of smoke and potentially trapping it near the surface.

Ozone levels are expected to remain in the Good to Moderate range due to cooler temperatures, cloud cover, and precipitation, though localized increases are possible in areas with persistent surface smoke.

Extended Forecast:

Pleasant weather is expected as we move toward the weekend, but lingering smoke may continue to influence air quality. Conditions will be monitored closely.

Next Forecast Update:

Thursday, July 31, 2025

07/29/2025 Forecast Update

Pollutant Overview

Ozone (O₃):
8-hour average ozone concentrations are expected to range from Good (Green AQI) to Moderate (Yellow AQI) through the forecast period.

Fine Particulates (PM-2.5):
24-hour average concentrations will remain mostly Moderate (Yellow AQI). However, elevated PM2.5 levels are expected across the Upper Peninsula Tuesday afternoon and evening as wildfire smoke drifts into the region.

Forecast Discussion

A weak boundary will continue moving slowly south through Michigan between Tuesday and Wednesday, maintaining hot and humid conditions across the southern half of the state for another day. This boundary will also serve as the focus for scattered thunderstorms, especially across central and northern Michigan.

Relief from the heat and humidity is expected past mid-week as high pressure from Canada moves in, bringing drier air and more comfortable temperatures through the remainder of the week.

For air quality:

• PM2.5 concentrations started Tuesday in the upper Good to low Moderate range but are already increasing in the northwest Upper Peninsula due to an incoming plume of wildfire smoke.

• This smoke is forecasted to continue moving through the Upper Peninsula during Tuesday and Wednesday, potentially resulting in elevated fine particulate levels.

• There is still some uncertainty regarding how far south the smoke will reach; upcoming forecasts will assess if central Michigan may also be impacted later in the week.

For ozone:

• Despite sunny skies, storm development is expected on Tuesday. The humid conditions across central and southern Michigan will generally limit ozone formation.

• While a few isolated sites may briefly reach low-end USG levels, most areas are expected to remain within the Moderate range.

• Ozone levels are expected to improve by Wednesday as northerly winds behind the front bring in cleaner air.

Extended Outlook

The extended forecast looks favorable with comfortable temperatures and sunny skies as high pressure settles over the region. However, we will continue to monitor smoke trends to determine if any lingering impacts on air quality will persist through the end of the week.

Next Forecast Update: Wednesday, July 30, 2025

07/28/2025 Forecast Update

Pollutant Overview

Ozone (O₃):
8-hour average ozone concentrations are expected to range from Good (Green AQI) to Moderate (Yellow AQI). A small chance exists for Unhealthy for Sensitive Groups (USG, Orange AQI) levels in southern Michigan.

Fine Particulates (PM-2.5):
24-hour average concentrations will be mostly Moderate (Yellow AQI) statewide. USG levels are possible in the Upper Peninsula on Tuesday due to wildfire smoke.

Forecast Discussion

A weak frontal boundary will gradually move through Michigan between late Monday and Wednesday, bringing opportunities for scattered thunderstorms. Ahead of this front, hot and muggy conditions will continue across much of the state.

Relief from the heat is expected past mid-week as high pressure from Canada sinks southward, ushering in cooler and less humid air along with more comfortable temperatures for the latter half of the week.

For air quality:

• PM2.5 levels on Monday morning were ranging between upper Good and low Moderate, and similar levels are expected into Tuesday. However, the Upper Peninsula may experience increasing PM2.5 concentrations on Tuesday as wildfire smoke enters the region. Forecast updates will evaluate if these levels will rise enough to warrant an advisory.

• With high pressure expected to settle in later this week, there is potential for smoke to linger and become trapped near the surface, which we will continue to monitor.

For ozone:

• A fair amount of sunshine is expected on Monday and Tuesday, with hot and humid conditions in place, especially across central and southern Michigan.

• While humidity generally limits ozone formation, isolated areas could still reach low-end USG levels.

• By Wednesday, air quality conditions should improve as northerly winds push through behind the front.

Extended Outlook

The extended forecast calls for comfortable temperatures and plentiful sunshine through the end of the week. However, smoke presence will continue to be evaluated to determine any lingering impact on air quality.

Next Forecast Update: Tuesday, July 29, 2025