Detroit Air Quality in Fall
Across 2019–2025, Detroit's fall (September–November) air quality had a median AQI of 55 (Moderate) over 637 monitored days in the Detroit-Warren-Dearborn, MI area. 1.4% of fall days (9 of 637) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 90.1% of days. The cleanest fall on record here was 2019 (median AQI 54, 0 days above 100) and the worst was 2022 (median 57, 4 days above 100, peak AQI 131).
- Good: 33.9%
- Moderate: 64.7%
- Unhealthy for Sensitive Groups: 1.4%
- Unhealthy or worse: 0.0%
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How is the air in Detroit in fall?
Moderate on a typical day: median AQI 55 across 2019–2025, with 1.4% of fall days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓33.9% of fall days were Good (AQI 0–50), 64.7% Moderate (51–100).
- ✓9 days of 637 reached AQI 101+; the fall peak was 134.
- ✓Cleanest month: October; worst month: November.
Frequently asked questions
What is the air quality like in Detroit in fall?▾
Across 2019–2025, the median daily AQI in Detroit in fall was 55 (Moderate). 33.9% of days were Good, 64.7% Moderate, and 1.4% reached Unhealthy for Sensitive Groups or worse, based on 637 monitored days in EPA's Air Quality System.
Is fall a good time for outdoor exercise in Detroit?▾
A typical fall day in Detroit is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 71 of fall days (1.4%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Detroit's fall air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 90.1% of fall days in Detroit. The highest fall AQI recorded in 2019–2025 was 134 (Unhealthy for Sensitive Groups), in 2022.
Detroit fall air quality, year by year
Detroit fall air quality by year (Detroit-Warren-Dearborn, MI, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 91 | 54 | 0 | 95 | PM2.5 |
| 2020 | 91 | 53 | 1 | 126 | PM2.5 |
| 2021 | 91 | 57 | 0 | 100 | PM2.5 |
| 2022worst | 91 | 57 | 4 | 131 | PM2.5 |
| 2023 | 91 | 58 | 2 | 120 | PM2.5 |
| 2024 | 91 | 53 | 1 | 134 | PM2.5 |
| 2025 | 91 | 53 | 1 | 108 | PM2.5 |
What fall air means in Detroit
A typical fall day in Detroit is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 71 of fall days (1.4%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Fall's median AQI of 55 is in line with Detroit's whole-year median of 58, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Fall AQI across every EPA metro area (296,275 metro-days, 2019–2025) is 40, so Detroit runs above the national Fall norm; 1.4% of its Fall days topped AQI 100 versus 1.5% nationally (about the same).
Within the season, October is the cleanest month (median AQI 53, 0.5% of days above 100) and November the worst (median 56, 3.3% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Detroit
The latest EPA AirNow observation puts Detroit's AQI at 29 (PM2.5). The figures above are multi-year season statistics, not today's reading.
View current Detroit air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Detroit-Warren-Dearborn, MI), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.