Springfield, IL Air Quality in Spring

Across 2019–2025, Springfield's spring (March–May) air quality had a median AQI of 44 (Good) over 644 monitored days in the Springfield, IL area. 0.9% of spring days (6 of 644) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 67.1% of days. The cleanest spring on record here was 2021 (median AQI 41, 0 days above 100) and the worst was 2023 (median 52, 6 days above 100, peak AQI 133).

44
Median AQI
Good
0.9%
Days above AQI 100
6 of 644 days
59
90th percentile AQI
worst 1 day in 10
133
Peak AQI
Unhealthy for Sensitive Groups
O3
Main pollutant
67.1% of days
72.7%
Good days
468 of 644
  • Good: 72.7%
  • Moderate: 26.4%
  • Unhealthy for Sensitive Groups: 0.9%
  • 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 300True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft

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QUICK ANSWER

How is the air in Springfield in spring?

Good on a typical day: median AQI 44 across 2019–2025, with 0.9% of spring days above AQI 100. Ground-level ozone is the main driver.

  • 72.7% of spring days were Good (AQI 0–50), 26.4% Moderate (51–100).
  • 6 days of 644 reached AQI 101+; the spring peak was 133.
  • Cleanest month: March; worst month: May.

Frequently asked questions

What is the air quality like in Springfield in spring?

Across 2019–2025, the median daily AQI in Springfield in spring was 44 (Good). 72.7% of days were Good, 26.4% Moderate, and 0.9% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.

Is spring a good time for outdoor exercise in Springfield?

A typical spring day in Springfield sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of spring days reached AQI 101+ in 2019–2025.

Which pollutant causes Springfield's spring air quality problems?

Ground-level ozone set the daily AQI on 67.1% of spring days in Springfield. The highest spring AQI recorded in 2019–2025 was 133 (Unhealthy for Sensitive Groups), in 2023.

Springfield spring air quality, year by year

Springfield spring air quality by year (Springfield, IL, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20199246077O3
20209244068O3
2021cleanest9241076O3
20229242080O3
2023worst92526133O3
20249243063O3
20259242082O3

What spring air means in Springfield

A typical spring day in Springfield sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of spring days reached AQI 101+ in 2019–2025.

Spring's median AQI of 44 is in line with Springfield's whole-year median of 44, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Spring AQI across every EPA metro area (307,196 metro-days, 2019–2025) is 43, so Springfield runs in line with the national Spring norm; 0.9% of its Spring days topped AQI 100 versus 0.8% nationally (about the same).

Within the season, March is the cleanest month (median AQI 43, 0.0% of days above 100) and May the worst (median 44, 2.8% above 100).

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 season 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.