Rockford Air Quality in 2019
In 2019, Rockford's air quality (Rockford, IL area) had a median daily AQI of 49 (Good) across 341 monitored days. 1 day (0.3%) reached Unhealthy for Sensitive Groups or worse, 182 were Good, and the year's peak AQI was 102 (Unhealthy for Sensitive Groups). Fine particulate matter (PM2.5) set the daily AQI on 233 of those days. The cleanest month of 2019 was September (median AQI 37, 0 days above 100) and the worst was July (median 53, 1 day above 100, peak 102).
- Good: 53.4%
- Moderate: 46.3%
- Unhealthy for Sensitive Groups: 0.3%
- Unhealthy or worse: 0.0%
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How was Rockford's air quality in 2019?
Good on a typical day: median AQI 49, with 1 day above AQI 100 out of 341 monitored — the 4th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2019: 102 (Unhealthy for Sensitive Groups).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 233 days.
- ✓Cleanest month: September; worst: July.
Frequently asked questions
What was the average AQI in Rockford in 2019?▾
EPA's Air Quality System puts Rockford's (Rockford, IL) median daily AQI for 2019 at 49, which is Good. 1 day were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 102.
Which month had the worst air quality in Rockford in 2019?▾
The cleanest month of 2019 was September (median AQI 37, 0 days above 100) and the worst was July (median 53, 1 day above 100, peak 102).
Was 2019 a good or bad year for Rockford's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 4th cleanest by days above AQI 100. 2019's median of 49 is in line with the area's typical annual median of 47.
Rockford month by month in 2019
Rockford air quality month by month, 2019 (Rockford, IL, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 27 | 53 | 0 | 71 | PM2.5 |
| February | 25 | 55 | 0 | 83 | PM2.5 |
| March | 31 | 51 | 0 | 83 | PM2.5 |
| April | 30 | 48 | 0 | 75 | O3 |
| May | 31 | 42 | 0 | 77 | O3 |
| June | 30 | 52 | 0 | 87 | PM2.5 |
| Julyworst | 31 | 53 | 1 | 102 | PM2.5 |
| August | 31 | 38 | 0 | 61 | O3 |
| Septembercleanest | 30 | 37 | 0 | 61 | O3 |
| October | 31 | 43 | 0 | 63 | PM2.5 |
| November | 17 | 58 | 0 | 81 | PM2.5 |
| December | 27 | 57 | 0 | 83 | PM2.5 |
How 2019 compares
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 4th cleanest by days above AQI 100.
2019's median of 49 is in line with the area's typical annual median of 47.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Rockford
The latest EPA AirNow observation puts Rockford's AQI at 30 (PM2.5). The figures above are multi-year annual 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.