Springfield, IL Air Quality in October
Across 2019–2025, Springfield's October air quality had a median AQI of 38 (Good) over 217 monitored days in the Springfield, IL area. 0.0% of October days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 63.1% of days. The cleanest October on record here was 2019 (median AQI 32, 0 days above 100) and the worst was 2022 (median 44, 0 days above 100, peak AQI 70).
- Good: 77.0%
- Moderate: 23.0%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Springfield
Today's main pollutant in Springfield is ground-level ozone (AQI 32). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Springfield in October?
Good on a typical day: median AQI 38 across 2019–2025, with 0.0% of October days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓77.0% of October days were Good (AQI 0–50), 23.0% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the October peak was 80.
- ✓Best October: 2019; worst October: 2022.
Frequently asked questions
What is the air quality like in Springfield in October?▾
Across 2019–2025, the median daily AQI in Springfield in October was 38 (Good). 77.0% of days were Good, 23.0% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is October a good time for outdoor exercise in Springfield?▾
A typical October day in Springfield sits in the Good range (median AQI 38), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of October days reached AQI 101+ in 2019–2025.
Which pollutant causes Springfield's October air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 63.1% of October days in Springfield. The highest October AQI recorded in 2019–2025 was 80 (Moderate), in 2022.
Springfield October air quality, year by year
Springfield October air quality by year (Springfield, IL, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 31 | 32 | 0 | 54 | PM2.5 |
| 2020 | 31 | 40 | 0 | 80 | PM2.5 |
| 2021 | 31 | 32 | 0 | 60 | PM2.5 |
| 2022worst | 31 | 44 | 0 | 70 | PM2.5 |
| 2023 | 31 | 37 | 0 | 75 | PM2.5 |
| 2024 | 31 | 41 | 0 | 71 | O3 |
| 2025 | 31 | 38 | 0 | 61 | O3 |
What October air means in Springfield
A typical October day in Springfield sits in the Good range (median AQI 38), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of October days reached AQI 101+ in 2019–2025.
October's median AQI of 38 is below Springfield's whole-year median of 44, making it one of the area's cleaner periods. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so Springfield runs in line with the national October norm; 0.0% of its October days topped AQI 100 versus 1.3% nationally (below average).
October is part of Springfield's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Springfield
The latest EPA AirNow observation puts Springfield's AQI at 32 (O3). The figures above are multi-year month statistics, not today's reading.
View current Springfield air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Springfield, 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.