Rockford Air Quality in Fall
Across 2019–2025, Rockford's fall (September–November) air quality had a median AQI of 43 (Good) over 622 monitored days in the Rockford, IL area. 0.6% of fall days (4 of 622) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 74.0% of days. The cleanest fall on record here was 2019 (median AQI 43, 0 days above 100) and the worst was 2024 (median 40, 3 days above 100, peak AQI 119).
- Good: 63.3%
- Moderate: 36.0%
- Unhealthy for Sensitive Groups: 0.6%
- Unhealthy or worse: 0.0%
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How is the air in Rockford in fall?
Good on a typical day: median AQI 43 across 2019–2025, with 0.6% of fall days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓63.3% of fall days were Good (AQI 0–50), 36.0% Moderate (51–100).
- ✓4 days of 622 reached AQI 101+; the fall peak was 119.
- ✓Cleanest month: October; worst month: September.
Frequently asked questions
What is the air quality like in Rockford in fall?▾
Across 2019–2025, the median daily AQI in Rockford in fall was 43 (Good). 63.3% of days were Good, 36.0% Moderate, and 0.6% reached Unhealthy for Sensitive Groups or worse, based on 622 monitored days in EPA's Air Quality System.
Is fall a good time for outdoor exercise in Rockford?▾
A typical fall day in Rockford sits in the Good range (median AQI 43), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of fall days reached AQI 101+ in 2019–2025.
Which pollutant causes Rockford's fall air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 74.0% of fall days in Rockford. The highest fall AQI recorded in 2019–2025 was 119 (Unhealthy for Sensitive Groups), in 2024.
Rockford fall air quality, year by year
Rockford fall air quality by year (Rockford, IL, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 78 | 43 | 0 | 81 | PM2.5 |
| 2020 | 91 | 46 | 0 | 71 | PM2.5 |
| 2021 | 91 | 44 | 0 | 87 | PM2.5 |
| 2022 | 89 | 43 | 0 | 82 | PM2.5 |
| 2023 | 91 | 48 | 0 | 83 | PM2.5 |
| 2024worst | 91 | 40 | 3 | 119 | PM2.5 |
| 2025 | 91 | 39 | 1 | 112 | PM2.5 |
What fall air means in Rockford
A typical fall day in Rockford sits in the Good range (median AQI 43), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of fall days reached AQI 101+ in 2019–2025.
Fall's median AQI of 43 is below Rockford's whole-year median of 47, making it one of the area's cleaner periods. Nationally, the median Fall AQI across every EPA metro area (296,275 metro-days, 2019–2025) is 40, so Rockford runs in line with the national Fall norm; 0.6% of its Fall days topped AQI 100 versus 1.5% nationally (about the same).
Within the season, October is the cleanest month (median AQI 41, 0.0% of days above 100) and September the worst (median 44, 1.9% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Rockford
The latest EPA AirNow observation puts Rockford's AQI at 22 (PM2.5). The figures above are multi-year season statistics, not today's reading.
View current Rockford air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Rockford, IL), 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.