Peoria Air Quality in Winter
Across 2019–2025, Peoria's winter (December–February) air quality had a median AQI of 48 (Good) over 542 monitored days in the Peoria, IL area. 0.0% of winter days (0 of 542) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 100.0% of days. The cleanest winter on record here was 2025 (median AQI 39, 0 days above 100) and the worst was 2021 (median 53, 0 days above 100, peak AQI 75).
- Good: 55.5%
- Moderate: 44.5%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Improve Indoor Air Quality
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How is the air in Peoria in winter?
Good on a typical day: median AQI 48 across 2019–2025, with 0.0% of winter days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓55.5% of winter days were Good (AQI 0–50), 44.5% Moderate (51–100).
- ✓0 days of 542 reached AQI 101+; the winter peak was 89.
- ✓Cleanest month: January; worst month: December.
Frequently asked questions
What is the air quality like in Peoria in winter?▾
Across 2019–2025, the median daily AQI in Peoria in winter was 48 (Good). 55.5% of days were Good, 44.5% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 542 monitored days in EPA's Air Quality System.
Is winter a good time for outdoor exercise in Peoria?▾
A typical winter day in Peoria 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 winter days reached AQI 101+ in 2019–2025.
Which pollutant causes Peoria's winter air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 100.0% of winter days in Peoria. The highest winter AQI recorded in 2019–2025 was 89 (Moderate), in 2021.
Peoria winter air quality, year by year
Peoria winter air quality by year (Peoria, IL, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 90 | 52 | 0 | 75 | PM2.5 |
| 2020 | 91 | 51 | 0 | 89 | PM2.5 |
| 2021worst | 86 | 53 | 0 | 75 | PM2.5 |
| 2022 | 59 | 52 | 0 | 85 | PM2.5 |
| 2023 | 65 | 45 | 0 | 76 | PM2.5 |
| 2024 | 69 | 43 | 0 | 89 | PM2.5 |
| 2025cleanest | 82 | 39 | 0 | 85 | PM2.5 |
What winter air means in Peoria
A typical winter day in Peoria 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 winter days reached AQI 101+ in 2019–2025.
Winter's median AQI of 48 is in line with Peoria's whole-year median of 45, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Winter AQI across every EPA metro area (278,620 metro-days, 2019–2025) is 40, so Peoria runs above the national Winter norm; 0.0% of its Winter days topped AQI 100 versus 0.6% nationally (about the same).
Within the season, January is the cleanest month (median AQI 47, 0.0% of days above 100) and December the worst (median 49, 0.0% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Peoria
The latest EPA AirNow observation puts Peoria's AQI at 42 (PM2.5). The figures above are multi-year season statistics, not today's reading.
View current Peoria air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Peoria, 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.