4Warn Weather – The 4Warn Weather Alert and Air Quality Alert have been extended through Friday as dangerous wildfire smoke continues to blanket Southeast Michigan, creating the worst air quality our region has experienced on record.
After a week that has already brought dangerous heat, severe thunderstorms, large hail, and now hazardous smoke, the focus remains squarely on the air we are breathing.
Michigan officials say this is the state’s worst wildfire smoke event in more than two decades of forecasting wildfire smoke.
Smoke levels have surpassed those measured during the major Canadian wildfire outbreaks of 2023 and 2025, and Michigan reached hazardous air quality statewide for the first time.
At times on Thursday morning, several air quality sensors across metro Detroit briefly reported Air Quality Index (AQI) values above 800. While those are individual sensor readings and not the official regional AQI, they illustrate just how concentrated the smoke became in some locations. Official readings peaked in the 600 to 700 range.
For much of Thursday, metro Detroit ranked among the cities with the worst air quality in the world, according to multiple global air quality monitoring networks.
Why this is so concerning
This is not simply haze or reduced visibility.
The smoke contains PM2.5, microscopic particles produced by wildfires. These particles are small enough to travel deep into the lungs and can even enter the bloodstream.
The Michigan Department of Environment, Great Lakes, and Energy (EGLE) says air quality reached the Hazardous category in most areas Thursday.
At this level, everyone can experience health effects and not just those with asthma or heart disease.
People may notice:
- Burning eyes, nose and throat
- Persistent coughing
- Shortness of breath
- Chest discomfort
- Headaches
- Fatigue
- Worsening asthma or other respiratory conditions
Those with heart disease, lung disease, children, older adults and pregnant individuals remain especially vulnerable, but during hazardous air quality even otherwise healthy adults should limit outdoor exposure.
What you should do
If you can smell smoke, your body is already telling you the air quality is poor.
Health officials recommend:
- Stay indoors as much as possible.
- Keep windows and doors closed.
- Run your air conditioning on recirculate if available.
- Use a HEPA air purifier if you have one.
- Avoid strenuous outdoor exercise, including running, yard work and outdoor sports.
- If you must spend extended time outside, a properly fitted N95 respirator offers significantly better protection than a cloth or surgical mask.
- Check on elderly neighbors, young children and anyone with chronic heart or lung disease.
The Air Quality Alert remains in effect through Friday, and smoke may continue to reduce visibility into Friday before gradually improving Friday night as winds shift.
Looking back at an extraordinary week
This has been one of the more remarkable stretches of weather Southeast Michigan has experienced this summer.
Wednesday featured:
- Heat index values as high as 108 degrees in Monroe County.
- Severe thunderstorms producing damaging winds and quarter-sized (1-inch) hail in Holly.
- Thick Canadian wildfire smoke arriving behind the storms, creating hazardous air quality across the region.
Experiencing dangerous heat, severe weather and hazardous wildfire smoke all within about 24 hours is highly unusual.
Storm chances return
Attention will begin shifting back toward thunderstorms heading into the weekend.
An isolated shower or thunderstorm is possible Friday afternoon and evening, although widespread severe weather is not expected Friday.
Saturday brings the greater concern.
A cold front moving into Michigan will increase instability, and thunderstorms are expected to become more numerous during the afternoon and evening.
The Storm Prediction Center currently places:
- Monroe County under a Level 2 of 5 (Slight Risk) for severe thunderstorms.
- That Slight Risk also extends into portions of southern Wayne County, including communities such as Flat Rock, Rockwood, Gibraltar and Trenton, along with parts of Lenawee County.
- The remainder of southeast Michigan, including Detroit and Ann Arbor, is under a Level 1 of 5 (Marginal Risk).
Any stronger storms Saturday could produce:
- Damaging wind gusts
- Large hail
- Frequent lightning
- Torrential rainfall
We will continue refining the timing and severity as newer forecast data arrives.
Better weather ahead
Once the weekend cold front passes, conditions improve significantly.
Sunday into much of next week looks:
- Less humid
- Cooler, with highs mainly in the lower to middle 80s
- Considerably cleaner air
- More comfortable for outdoor activities
- A couple of chances of rain
After an exceptionally active week, Southeast Michigan is finally expected to return to more typical midsummer weather.
Share your photos of the smoky skies with Local 4 at MIPics. You might see one of them on TV.