Grand Rapids Air Quality in September
Across 2019–2025, Grand Rapids's September air quality had a median AQI of 48 (Good) over 210 monitored days in the Grand Rapids-Wyoming, MI area. 0.5% of September days (1 of 210) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 70.0% of days. The cleanest September on record here was 2020 (median AQI 41, 0 days above 100) and the worst was 2021 (median 43, 1 day above 100, peak AQI 143).
- Good: 53.8%
- Moderate: 45.7%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 0.0%
Extra Protection for Grand Rapids Homes
Air quality in Grand Rapids is moderate (AQI 53), with fine particles (PM2.5) the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
Recommended: Coway AP-1512HH Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
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How is the air in Grand Rapids in September?
Good on a typical day: median AQI 48 across 2019–2025, with 0.5% of September days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓53.8% of September days were Good (AQI 0–50), 45.7% Moderate (51–100).
- ✓1 day of 210 reached AQI 101+; the September peak was 143.
- ✓Best September: 2020; worst September: 2021.
Frequently asked questions
What is the air quality like in Grand Rapids in September?▾
Across 2019–2025, the median daily AQI in Grand Rapids in September was 48 (Good). 53.8% of days were Good, 45.7% Moderate, and 0.5% 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 Grand Rapids?▾
A typical September day in Grand Rapids sits in the Good range (median AQI 48), 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 Grand Rapids's September air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 70.0% of September days in Grand Rapids. The highest September AQI recorded in 2019–2025 was 143 (Unhealthy for Sensitive Groups), in 2021.
Grand Rapids September air quality, year by year
Grand Rapids September air quality by year (Grand Rapids-Wyoming, MI, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 30 | 43 | 0 | 67 | PM2.5 |
| 2020cleanest | 30 | 41 | 0 | 62 | PM2.5 |
| 2021worst | 30 | 43 | 1 | 143 | PM2.5 |
| 2022 | 30 | 47 | 0 | 61 | PM2.5 |
| 2023 | 30 | 54 | 0 | 87 | PM2.5 |
| 2024 | 30 | 51 | 0 | 100 | PM2.5 |
| 2025 | 30 | 58 | 0 | 87 | PM2.5 |
What September air means in Grand Rapids
A typical September day in Grand Rapids sits in the Good range (median AQI 48), 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 48 is in line with Grand Rapids's whole-year median of 51, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median September AQI across every EPA metro area (100,699 metro-days, 2019–2025) is 43, so Grand Rapids runs above the national September norm; 0.5% of its September days topped AQI 100 versus 2.7% nationally (below average).
September is part of Grand Rapids's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Grand Rapids
The latest EPA AirNow observation puts Grand Rapids's AQI at 53 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Grand Rapids air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Grand Rapids-Wyoming, 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.