Metro area air quality · 2024
Effingham, IL
Median AQI 41 (Good). 90.4% of monitored days rated Good across this metro's EPA monitoring network.
- 41
- Median AQI
- 90.4%
- Good-air days
- 0
- Unhealthy days
- 86%
- Cleaner than US metros
Aggregated from EPA Air Quality System (2024), 240 monitored days. EPA AQS →
The verdict
The Effingham, IL metro runs good on the EPA scale — a median AQI of 41 with 90.4% of 240 monitored days in the Good band.
- 41
- median AQI · Good
- 90.4%
- days rated Good
- 86%
- cleaner than US metros
- 101
- worst single reading
No day crossed into the Unhealthy tier across the metro's monitors in 2024.
Insights: Effingham, IL metro. Aggregated EPA AQS monitors across this Core-Based Statistical Area logged a median Air Quality Index of 41 over 240 measured days in 2024, which corresponds to a Good band and a Excellent metro-wide health grade. The monitored-day split lands at 217 Good days (90%), 22 Moderate (9%), and 1 Unhealthy-for-Sensitive-Groups (0%). The 90th-percentile AQI finished at 50 while the highest single-day reading hit 101 (USG). Metro residents averaged roughly 27.1 clean-air days per 30-day window across the reporting year.
Across the 2020–2024 trend window, good days shifted by +61 and the median AQI moved +4 points, which classifies the multi-year trajectory as improving. The metro avoided any Unhealthy-tier days entirely, an outcome that typically reflects favorable wind patterns, lower industrial density, or effective regional emission controls. Metros with comparable AQI profiles include Allentown-Bethlehem-Easton, PA-NJ (68.3% good, AQI 41); Ashtabula, OH (83.7% good, AQI 41); Bowling Green, KY (76.8% good, AQI 41).
Air Quality Summary
Median AQI
41
Good
Good Days
90.4%
217 of 240 days
Max AQI
101
USG
Health Grade
Excellent
90th pct: 50
AQI Day Breakdown (2024)
Distribution of 240 monitored days across EPA AQI categories.
Good
217
90%
Moderate
22
9%
USG
1
0%
Unhealthy
0
0%
Very Unhealthy
0
0%
Hazardous
0
0%
Health Impact Assessment
The Effingham, IL metro area's air quality is rated Excellent based on 90.4% good air days. No unhealthy air days were recorded in 2024.
Air quality is generally acceptable. Unusually sensitive people should monitor real-time conditions at AirNow.gov during high-pollution events.
How does the Effingham, IL metro compare?
How Effingham, IL compares
5-Year Air Quality Trend
Air quality is improving in the Effingham, IL metro. Best year: 2021 (226 good days).
| Year | Good | Moderate | Unhealthy | Median AQI | Max AQI |
|---|---|---|---|---|---|
| 2020 | 156 | 10 | 0 | 37 | 84 |
| 2021 | 226 | 11 | 0 | 37 | 77 |
| 2022 | 215 | 24 | 0 | 38 | 100 |
| 2023 | 182 | 50 | 0 | 44 | 140 |
| 2024 | 217 | 22 | 0 | 41 | 101 |
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Frequently Asked Questions
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How does Effingham, IL compare to other metro areas? ▼
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by CBSA dataset, 2020–2024. The AQS collects ambient air monitoring data from state, local, and tribal monitoring agencies across the United States.
Metrics: Air Quality Index (AQI) is calculated using EPA-standard breakpoints for six criteria pollutants: PM2.5, PM10, Ozone, NO2, CO, and SO2. Median AQI, max AQI, and 90th percentile AQI are computed from daily measurements. Good days percentage reflects days with AQI 0–50.
Coverage: 501 metro areas (Core Based Statistical Areas). Only metros with active monitoring stations are included. Unmonitored areas are not represented.
Read our methodology , how this data is sourced, computed, and verified.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by CBSA summary files (metro-level) · 2020–2024