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

07/24/2025 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 for USG (Orange AQI) exists in southeastern and southwestern Michigan on Thursday.

Fine Particulates (PM-2.5):
PM2.5 concentrations will be Moderate across southern Michigan, with USG levels developing in the Upper Peninsula Thursday afternoon, expanding into the northern Lower Peninsula by early Friday morning. There is a possibility of short-term Unhealthy (Red AQI) spikes in localized areas.

Forecast Discussion

A frontal boundary advancing south through Michigan will be the focal point for storm development and air quality impacts over the next few days.

• Thursday: Warm and humid conditions persist with sunshine and temperatures reaching 80s in the north and 90s in the south. Heat indices may approach 100°F in parts of southern Michigan.

• Precipitation will move into northern areas late Thursday, spreading further south by early Friday as the front progresses.

As the front moves south, Canadian wildfire smoke will be pulled into Michigan. Forecast models indicate:

• Smoke entering the Upper Peninsula Thursday afternoon

• The smoke plume will drift into the northern Lower Peninsula early Friday morning, potentially reaching central areas by midday Friday.

PM2.5 levels are expected to rise into the USG (Orange AQI) range in the advisory areas. There is also a chance for hourly concentrations to briefly reach the Unhealthy (Red AQI) range. The advisory will be reevaluated Friday morning to determine if expansion further south or an extension into Saturday is necessary.

For ozone, some monitors reached low-end USG levels in southeastern Michigan on Wednesday. A similar risk exists for Thursday, particularly in southeastern and southwestern Michigan, though most areas are expected to remain in the Moderate range.

Extended Outlook

The extended forecast remains uncertain due to:

• The path and intensity of additional smoke plumes

• The timing of precipitation

• The ongoing impact of heat and humidity on air quality levels

Further forecast updates will be issued as conditions develop.

07/23/2025 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 (Orange AQI), particularly in parts of southern Lower Michigan.

Fine Particulates (PM-2.5):
24-hour average concentrations will remain mostly Moderate (Yellow AQI) statewide, with potential increases due to wildfire smoke later in the forecast period.

Forecast Discussion

A frontal boundary is progressing south through Michigan, bringing a shift in weather and air quality conditions:

• On Wednesday, the front will bring precipitation to the Upper Peninsula and parts of Northern Lower Michigan, while sunny skies continue further south.

• Temperatures will rise into the 80s on Wednesday and climb into the 90s on Thursday across much of the Lower Peninsula.

• Heat indices may approach 100°F in the south on Thursday. With the increasing humidity, outdoor conditions will become uncomfortable, and heat safety precautions are advised.

For air quality:

• PM2.5 levels have remained in the upper Good to low Moderate range, and similar levels are expected through Wednesday.

• Smoke models suggest a plume of wildfire smoke may move into the Upper Peninsula Thursday afternoon, gradually pushing into southern Michigan by late Thursday into Friday. If current trends continue, PM2.5 may approach USG levels in affected regions. This will be closely monitored for potential air quality alerts.

• Ozone levels are forecast to remain Moderate, with Good conditions in the north. Sunshine and warming temperatures may allow for localized increases on Wednesday, but increased humidity and cloud cover Thursday will likely limit ozone formation. A small chance exists for isolated USG levels, though not enough to warrant a pollution alert at this time.

Extended Outlook

There is continued uncertainty in the extended forecast regarding:

• The timing and intensity of precipitation

• The trajectory of additional smoke plumes

• The influence of lingering heat and humidity on pollutant levels

Further forecast updates will provide additional detail as conditions evolve through the end of the week.

07/22/2025 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 for Unhealthy for Sensitive Groups (Orange AQI) exists, particularly in southern areas.

Fine Particulates (PM-2.5):
24-hour average concentrations will be mostly Moderate (Yellow AQI) statewide, with some influence from surface-level smoke.

Forecast Discussion

Two key features are shaping Michigan's weather between Tuesday and Wednesday:

• A high-pressure system positioned east of the state will keep conditions mostly quiet.

• A frontal boundary to the northwest will begin bringing precipitation to the western Upper Peninsula later Tuesday. This front will slowly move south through Thursday, eventually impacting the Lower Peninsula with potential rain and storms.

In the meantime, temperatures will climb into the 80s and 90s, and humidity levels will rise, creating more uncomfortable outdoor conditions as the week progresses.

As for air quality:

• Fine particulate levels (PM2.5) will remain mostly Moderate, as lingering smoke from Wisconsin and Lake Michigan shifts back over the region. No significant spikes are expected.

• Ozone concentrations may also increase slightly due to this smoke, but rising dew points will likely help limit formation. A small chance for USG ozone levels exists in southern Michigan, though Good to Moderate conditions are expected across most areas.

Extended Outlook

Smoke model data suggests another potential smoke intrusion behind the frontal boundary on Thursday, which could impact air quality later in the week.

There remains uncertainty in the extended forecast regarding:

• Timing of precipitation

• Duration of lingering heat

• Potential for wildfire smoke return

Future updates will provide more detail as conditions develop.

07/21/2025 Forecast Update

Pollutant Overview

Ozone (O₃):
8-hour average ozone concentrations are expected to remain Good (Green AQI) to Moderate (Yellow AQI). There is a small chance of Unhealthy for Sensitive Groups (Orange AQI) at select southern Michigan monitors on Tuesday afternoon.

Fine Particulates (PM-2.5):
24-hour average concentrations will be mostly Moderate (Yellow AQI), with improving conditions across southern Michigan as lingering wildfire smoke clears.

Forecast Discussion

Fine particulate concentrations increased across Michigan late Sunday into early Monday due to a north-to-south moving wildfire smoke plume. Hourly PM2.5 levels reached the USG (Orange AQI) range in parts of the southwest, but daily averages remained Moderate across the state.

High pressure will remain in control through Tuesday, bringing plenty of sunshine, comfortable temperatures, and low humidity. Beginning Wednesday, high pressure will shift east as an upper-level ridge (heat dome) builds over the southeastern U.S., bringing hotter, more humid air into Michigan by midweek. A boundary approaching from the north will introduce storm chances beginning Wednesday or Thursday.

For air quality:

• PM2.5 levels are expected to improve on Monday, with Good conditions in northern areas and Moderate in the south. Lingering smoke may lead to continued Moderate levels on Tuesday, but higher concentrations are not expected.

• Ozone levels will range from Good to Moderate, though surface smoke may enhance ozone formation in some areas. A few southern monitors could briefly reach USG (Orange AQI) levels Tuesday afternoon.

We will continue monitoring conditions and will update the forecast if ozone levels appear likely to rise further as heat and humidity build midweek.

Extended Outlook

Uncertainty remains regarding additional wildfire smoke moving into the region with the expected frontal boundary later this week. Forecasts will be updated accordingly as conditions evolve.

07/18/2025 Forecast Update

Pollutant Overview

Ozone (O₃):

8-hour average concentrations are expected to remain Good (Green AQI), with scattered periods of Moderate (Yellow AQI) throughout the forecast period.

Fine Particulates (PM-2.5):
24-hour average concentrations are also expected to be Good (Green AQI) overall, with isolated instances of Moderate (Yellow AQI).

Forecast Discussion

A cooler, drier air mass will settle over Michigan following Thursday’s clouds. Friday will feel refreshing, with highs near 80°F and no wildfire smoke in the region—setting the stage for excellent air quality to begin the weekend.

Saturday brings a chance of thunderstorms and potential severe weather. Morning showers could reduce afternoon storm intensity by limiting instability. However, if the morning stays dry, the likelihood of stronger afternoon storms increases. Regardless, Saturday is likely to be wet.

Sunday will see a return to sunny skies and comfortable temperatures in the low 80s, accompanied by light north-northeast winds. Air quality is expected to remain mostly Good for both ozone and fine particulates.

Looking ahead, summer weather returns midweek, with temperatures possibly reaching the low 90s and continuing into the following weekend.

Extended Outlook

Air quality is not expected to be an issue as the upcoming work week begins.

07/14/2025 Forecast Update

Current Alerts & Advisories

• A Statewide Air Quality Alert remains in effect for Monday, July 14, due to Fine Particulates (PM-2.5).

• An Air Quality Advisory for Ozone is in effect for Tuesday, July 15, in the following Southeast Michigan counties:
  Livingston, Macomb, Monroe, Oakland, St. Clair, Washtenaw, and Wayne.

Pollutant Overview

Ozone (O₃):

• 8-hour average concentrations will range from Good (Green AQI) to Moderate (Yellow AQI) across most of the state.

• Unhealthy for Sensitive Groups (Orange AQI) is expected in Southeast Michigan on Tuesday.

Fine Particulates (PM-2.5):

• Early in the week, levels are expected to be Moderate (Yellow AQI).

• Conditions should improve midweek, with a mix of Good (Green AQI) and Moderate levels expected statewide.

Forecast Discussion

Another episode of elevated wildfire smoke affected Michigan over the weekend, leading to alerts that extend through Monday. The heaviest smoke is now shifting east into Ontario, but Michigan will remain under alert until conditions fully clear. By Tuesday, air quality is expected to improve statewide, though brief morning impacts may still occur in the far western Upper Peninsula.

A separate smoke plume over northern Minnesota is not expected to reach Michigan. No additional wildfire smoke-related issues are forecasted at this time, but conditions will continue to be monitored and updated as necessary.

Tuesday Ozone Advisory

Weather conditions on Tuesday, July 15, will be favorable for ozone formation in Southeast Michigan, including:

• High temperatures near 90°F

• Sunny skies

• Light winds

• Dew points in the mid-60s

These conditions can lead to elevated ozone concentrations, prompting the issuance of an advisory. Sensitive groups should limit prolonged outdoor activity. A change in weather is expected Wednesday afternoon, bringing cloud cover and rain ahead of a cold front, which should end this brief ozone event.

Extended Outlook

A cold front is forecasted to pass through Thursday, bringing:

• Cooler temperatures

• Lower humidity

• Improved air quality

No air quality issues are currently expected for the upcoming weekend.

07/13/2025 Forecast Update

Statewide Air Quality Alert in Effect

A statewide Air Quality Alert has been issued for fine particulate (PM-2.5) due to wildfire smoke from Canada impacting Michigan through Monday.

Pollutant Overview

PM-2.5 (Fine Particulate):

• Upper Peninsula & Northern Lower Michigan: Unhealthy (Red AQI) to USG (Orange AQI)

• Central Michigan: Unhealthy to USG

• Southern Michigan: USG to Moderate (Yellow AQI)

Ozone:

• Generally in the Good to Moderate range statewide

• Scattered USG possible Monday, especially in southern Michigan due to warmer temperatures and light winds

Forecast Details

Wildfire smoke continues to move into Michigan Sunday, spreading south and east throughout the day. Additional smoke plumes are forecast for Monday. Expect elevated fine particulate levels, particularly in northern and central Michigan.

By Monday, a southerly wind shift could increase ozone levels slightly, with the potential for a few areas to reach the USG range in the southern part of the state.

Looking Ahead

Dry and warm conditions are expected to persist into Tuesday. Without a significant airmass change, air quality concerns may continue into midweek.

Next Forecast Update: Monday, July 14, 2025

07/12/2025 Forecast Update

FORECAST SUMMARY: Saturday, July 12, 2025 - Sunday, July 13, 2025

Air Quality Alert for fine particulate begins at noon on Saturday, July 12 for the western Upper Peninsula, expanding statewide on Sunday, July 13 through noon Monday, July 14.

Saturday Alert Counties:
Baraga, Dickinson, Gogebic, Houghton, Iron, Keweenaw, Marquette, Ontonagon

Sunday–Monday Alert:
Statewide

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

PM-2.5:

• Saturday: Daily average fine particulate concentrations expected to range between Very Unhealthy (Purple AQI) to Unhealthy (Red AQI) in the western Upper Peninsula, with levels remaining mostly Moderate elsewhere.

• Sunday: Concentrations will range from Very Unhealthy to Unhealthy in northern Michigan to USG (Orange AQI) and Moderate in southern regions.

FORECAST DISCUSSION:
A cold front will move through the region on Saturday, bringing chances of showers and storms. Behind the front, high pressure will build in on Sunday, ending precipitation from west to east. Warm, dry conditions are expected into the start of the workweek.

The primary air quality concern is elevated PM-2.5 levels from wildfire smoke moving down from Canada. Current smoke models show a concentrated plume entering the western Upper Peninsula by Saturday afternoon, moving across the U.P. and into Lower Michigan from late Saturday through Sunday.

As this occurs, elevated PM-2.5 concentrations are anticipated statewide. Based on model trends:

• Very Unhealthy to Unhealthy levels are expected across the Upper Peninsula and northern Lower Michigan.

• Unhealthy to USG levels in central portions of the state.

• USG to Moderate levels further south.

Forecast updates will continue, with the next one scheduled for Sunday morning, which will also assess whether the air quality alert needs to extend beyond noon on Monday.

Looking ahead, ozone may become a concern into early next week, as southerly winds and warmer conditions return. This will also be reviewed in the next update.

EXTENDED FORECAST:
Dry, warm weather continues into next week. Conditions may support elevated ozone and/or PM-2.5 levels later in the period. Updates will be provided as needed.

Next forecast update: Sunday, July 13, 2025

07/10/2025 Forecast Update

Air Quality Outlook – July 10–12, 2025

As we head into the weekend, air quality remains mostly stable across lower Michigan. Here’s what to expect in the days ahead.

Quick Summary

• Ozone (O₃): Expected to remain in the Good (Green AQI) to Moderate (Yellow AQI) range

• Fine Particulate Matter (PM2.5): Daily averages will fall between upper Good and low Moderate

Weather & Air Quality Breakdown

Thursday (July 10):

• High pressure will bring calm conditions and light winds

• Ozone and PM2.5 levels expected to stay in the Good to low-Moderate range

Friday (July 11):

• A disturbance brings increasing clouds and potential rain

• These conditions will help limit ozone buildup

• Fine particulate levels will hover in the low-Moderate range

Saturday (July 12):

• A warm front moves north, followed by a cold front later in the day

• Precipitation and cloud cover will likely keep ozone in check

• Wildfire smoke from Canada may move into the region by late Saturday—forecasters are monitoring this closely for potential impacts on PM2.5

Extended Outlook

Looking ahead to early next week, forecast models show dry and warm conditions returning. This could lead to rising pollution levels, especially ozone. We’ll continue to monitor for any changes.

Next Update

The next air quality update will be posted on Saturday, July 12, 2025. Check back then for the latest conditions and outlook.

07/07/2025 Forecast Update

Weekly Air Quality Outlook – July 7–10, 2025

Welcome back from the 4th of July holiday! Here’s what to expect this week for air quality across lower Michigan.

Quick Summary

• Ozone: Ranging from Good (Green AQI) to Moderate (Yellow AQI)

• Fine Particulate Matter (PM2.5): Expected to remain between upper Good and Moderate levels

After the Fireworks

Fireworks over the weekend caused short-term spikes in fine particulate levels, with some areas exceeding 150 µg/m³. Thankfully, by July 5th, conditions had already improved, and daily averages returned to Moderate or better.

Weather & Air Quality Breakdown

Monday (July 7):

• Clouds will clear from northwest to southeast

• Some wildfire smoke aloft, but no major ground-level impacts expected

• Cooler northerly flow will help suppress ozone formation

Tuesday-Thursday:

• These are the most likely days to see Moderate ozone levels, especially in southern Michigan

• A midweek disturbance could bring brief showers

Friday:

• As high pressure moves out, southerly winds return

• May lead to a slight uptick in ozone levels — stay tuned for Thursday's update

Extended Forecast

Looking into the weekend, models show rain possible Saturday, which could help keep pollution levels down. Overall, no air quality category is expected to exceed Moderate during this forecast period.

Next Update

We’ll post our next air quality update on Thursday, July 10, 2025. Be sure to check back or follow us on social media for the latest information.

07/04/2025 Forecast Update

FORECAST SUMMARY: Friday July 4, 2025, through Monday July 7, 2025

Ozone:

Ozone concentrations are expected to be in the Moderate to USG range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Moderate to USG range.

Air Quality Advisory for Ozone on July 4, 2025, for the following counties:

Allegan, Berrien, Kent, Muskegon, Ottawa, Van Buren

Air Quality Advisory for PM-2.5 on July 4, 2025, for the following counties:

Livingston, Macomb, Monroe, Oakland, St. Clair, Washtenaw, Wayne

FORECAST DISCUSSION:

Two Air Quality Advisories are in place today, July 4th, one in west Michigan along the Lake Michigan shoreline for Ozone, and the other is in metro Detroit for PM-2.5.

The environment over Lake Michigan and along the Lake Michigan shoreline is primed for Ozone development. These conditions will persist tomorrow, Saturday, so the current Air Quality Advisory for Ozone will be extended through Saturday, July 5th. Surface temperatures will increase into the low-to-mid 90s with winds shifting to southwesterly, both near the surface and in the upper-levels. Additionally, upper-level temperatures will be near twenty degrees Celsius, which is ideal for the Ozone photochemical reaction to occur. These conditions will be present over southeast Michigan as well, mixing with a potentially dirty atmosphere, so an Air Quality Advisory for Ozone will be issued for the metro Detroit area tomorrow, Saturday.

For PM-2.5, the current Advisory in place will be extended through Saturday, July 5th. Light winds will continue through today, Friday, and last until early Saturday afternoon when winds are expected to pick up. PM-2.5 concentrations are expected to improve throughout Saturday afternoon as winds pick up.

Come Sunday, a Low-pressure system and associated frontal boundary will cross over the state bringing NNW winds and a chance of rain showers. This will clean out the atmosphere and improve overall air quality through Monday, July 7th.

EXTENDED FORECAST:

Air quality looks Good to start off the next week.

07/03/2025 Forecast Update

FORECAST SUMMARY: Thursday July 3, 2025, through Friday July 4, 2025

Ozone:

Ozone concentrations are expected to be in the Moderate to USG range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Moderate to USG range.

Air Quality Advisory for Ozone on July 4, 2025, for the following counties:

 Allegan, Berrien, Kent, Muskegon, Ottawa, Van Buren

 FORECAST DISCUSSION:

Holiday travel is in full swing and firework displays are booming across the Great Lakes state. Weather-wise, with the exception of the western Upper Peninsula, one could not ask for a better 4th of July with temperatures well into the 80s, light winds and plenty of sunshine. This is due, in part, to a High-pressure system moving across the region and along the eastern Lake Huron shoreline. Regionally, this pressure system will hang around through Saturday, providing similar weather conditions then as well.

Unfortunately, however, poor air quality is expected as well due to the aforementioned weather set up. For the Lake Michigan shoreline, an Air Quality Advisory for Ozone is in place for Friday July 4 due to light SSW winds, mostly sunny skies and surface temperatures well into the 80s creating a conducive environment for Ozone development. There is a chance of clouds in the early to mid-afternoon but due to the proper ingredients in place, along with firework displays adding more ingredients for Ozone to develop in the atmosphere, USG-level Ozone should be expected. Although this forecast will be updated Friday morning, it can be expected to see USG-level Ozone along the Lake Michigan shoreline on Saturday as well.

06/30/2025 Forecast Update

FORECAST SUMMARY: Monday June 30, 2025, Thursday July 3, 2025

Ozone:

Ozone concentrations are expected to be in the Good to Moderate range.

PM-2.5:

PM-2.5 concentrations are expected to be in the Good to low-Moderate range.

FORECAST DISCUSSION:

Summer is in full swing as we round off the month of June and enter July this week. Today, Monday, will see hot temperatures return along with high dewpoint temperatures which will increase humidity across the state. The mixture of hot temperatures, humid air, and an impending cold front will cause popup rain showers and potential storms throughout the day today. Once the cold front moves off to the southeast overnight, Tuesday will be slightly cooler in the upper-70s to low-80s, and drier air with dewpoints in the low-50s. This trend continues into Wednesday as a High-pressure moves in throughout the day and is expected to hang around to start off the holiday weekend.

With the exception of Tuesday, winds throughout this week will be from the WSW, which may pose a threat of increases in Ozone, but for the time being, there appears to be no threat of widespread USG-level Ozone for multiple hours due to the aforementioned cold front cleaning out the atmosphere later Monday into Tuesday. Also, the cooler temperatures on Tuesday and into Wednesday will help keep Ozone concentrations at bay. Concentrations may approach the USG range, but nothing to cause an Advisory to be issued. For PM-2.5, there appears to be regional wildfire smoke across the Midwest this week which may increase PM-2.5 concentrations, but nothing more than mid-to-high Moderate at the worst. PM-2.5 concentrations may also see an increase throughout this week and into the weekend due to 4th of July festivities, especially fireworks. This forecast will be updated on Thursday to get a better look at conditions for the holiday weekend ahead.

EXTENDED FORECAST:

Hot temperatures return for the holiday weekend along with sunshine and a chance for rain on Saturday. Expected air quality will be forecasted on Thursday for the weekend ahead, but general Moderate conditions can be expected at this time, with a chance at hourly USG concentrations.

Next Forecast update: Thursday July 3, 2025