Rockford Air Quality in January
Across 2019–2025, Rockford's January air quality had a median AQI of 47 (Good) over 206 monitored days in the Rockford, IL area. 0.0% of January days (0 of 206) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 100.0% of days. The cleanest January on record here was 2025 (median AQI 27, 0 days above 100) and the worst was 2021 (median 56, 0 days above 100, peak AQI 78).
- Good: 55.8%
- Moderate: 44.2%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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How is the air in Rockford in January?
Good on a typical day: median AQI 47 across 2019–2025, with 0.0% of January days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓55.8% of January days were Good (AQI 0–50), 44.2% Moderate (51–100).
- ✓0 days of 206 reached AQI 101+; the January peak was 87.
- ✓Best January: 2025; worst January: 2021.
Frequently asked questions
What is the air quality like in Rockford in January?▾
Across 2019–2025, the median daily AQI in Rockford in January was 47 (Good). 55.8% of days were Good, 44.2% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 206 monitored days in EPA's Air Quality System.
Is January a good time for outdoor exercise in Rockford?▾
A typical January day in Rockford sits in the Good range (median AQI 47), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of January days reached AQI 101+ in 2019–2025.
Which pollutant causes Rockford's January air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 100.0% of January days in Rockford. The highest January AQI recorded in 2019–2025 was 87 (Moderate), in 2021.
Rockford January air quality, year by year
Rockford January air quality by year (Rockford, IL, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 27 | 53 | 0 | 71 | PM2.5 |
| 2020 | 31 | 41 | 0 | 78 | PM2.5 |
| 2021worst | 31 | 56 | 0 | 78 | PM2.5 |
| 2022 | 31 | 49 | 0 | 87 | PM2.5 |
| 2023 | 31 | 52 | 0 | 77 | PM2.5 |
| 2024 | 31 | 41 | 0 | 74 | PM2.5 |
| 2025cleanest | 24 | 27 | 0 | 65 | PM2.5 |
What January air means in Rockford
A typical January day in Rockford sits in the Good range (median AQI 47), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of January days reached AQI 101+ in 2019–2025.
January's median AQI of 47 is in line with Rockford's whole-year median of 47, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median January AQI across every EPA metro area (95,602 metro-days, 2019–2025) is 39, so Rockford runs above the national January norm; 0.0% of its January days topped AQI 100 versus 0.7% nationally (about the same).
January is part of Rockford's winter season (December, January, February); the winter page pools all three months.
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 month 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.