Flint Air Quality in September
Across 2019–2025, Flint's September air quality had a median AQI of 36 (Good) over 210 monitored days in the Flint, MI area. 0.0% of September days (0 of 210) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 75.7% of days. The cleanest September on record here was 2020 (median AQI 32, 0 days above 100) and the worst was 2024 (median 42, 0 days above 100, peak AQI 64).
- Good: 89.5%
- Moderate: 10.5%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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How is the air in Flint in September?
Good on a typical day: median AQI 36 across 2019–2025, with 0.0% of September days above AQI 100. Ground-level ozone is the main driver.
- ✓89.5% of September days were Good (AQI 0–50), 10.5% Moderate (51–100).
- ✓0 days of 210 reached AQI 101+; the September peak was 71.
- ✓Best September: 2020; worst September: 2024.
Frequently asked questions
What is the air quality like in Flint in September?▾
Across 2019–2025, the median daily AQI in Flint in September was 36 (Good). 89.5% of days were Good, 10.5% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is September a good time for outdoor exercise in Flint?▾
A typical September day in Flint sits in the Good range (median AQI 36), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of September days reached AQI 101+ in 2019–2025.
Which pollutant causes Flint's September air quality problems?▾
Ground-level ozone set the daily AQI on 75.7% of September days in Flint. The highest September AQI recorded in 2019–2025 was 71 (Moderate), in 2024.
Flint September air quality, year by year
Flint September air quality by year (Flint, MI, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 30 | 34 | 0 | 71 | O3 |
| 2020cleanest | 30 | 32 | 0 | 71 | O3 |
| 2021 | 30 | 35 | 0 | 48 | O3 |
| 2022 | 30 | 41 | 0 | 67 | PM2.5 |
| 2023 | 30 | 36 | 0 | 53 | O3 |
| 2024worst | 30 | 42 | 0 | 64 | O3 |
| 2025 | 30 | 38 | 0 | 54 | O3 |
What September air means in Flint
A typical September day in Flint sits in the Good range (median AQI 36), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of September days reached AQI 101+ in 2019–2025.
September's median AQI of 36 is below Flint's whole-year median of 42, making it one of the area's cleaner periods. Nationally, the median September AQI across every EPA metro area (100,699 metro-days, 2019–2025) is 43, so Flint runs below the national September norm; 0.0% of its September days topped AQI 100 versus 2.7% nationally (below average).
September is part of Flint's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Flint
The latest EPA AirNow observation puts Flint's AQI at 20 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Flint air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Flint, 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.