Rockford Air Quality in April

Across 2019–2025, Rockford's April air quality had a median AQI of 44 (Good) over 210 monitored days in the Rockford, IL area. 0.0% of April days (0 of 210) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 58.1% of days. The cleanest April on record here was 2022 (median AQI 41, 0 days above 100) and the worst was 2020 (median 48, 0 days above 100, peak AQI 74).

44
Median AQI
Good
0.0%
Days above AQI 100
0 of 210 days
57
90th percentile AQI
worst 1 day in 10
80
Peak AQI
Moderate
O3
Main pollutant
58.1% of days
70.0%
Good days
147 of 210
  • Good: 70.0%
  • Moderate: 30.0%
  • Unhealthy for Sensitive Groups: 0.0%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How is the air in Rockford in April?

Good on a typical day: median AQI 44 across 2019–2025, with 0.0% of April days above AQI 100. Ground-level ozone is the main driver.

  • 70.0% of April days were Good (AQI 0–50), 30.0% Moderate (51–100).
  • 0 days of 210 reached AQI 101+; the April peak was 80.
  • Best April: 2022; worst April: 2020.

Frequently asked questions

What is the air quality like in Rockford in April?

Across 2019–2025, the median daily AQI in Rockford in April was 44 (Good). 70.0% of days were Good, 30.0% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.

Is April a good time for outdoor exercise in Rockford?

A typical April day in Rockford 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 April days reached AQI 101+ in 2019–2025.

Which pollutant causes Rockford's April air quality problems?

Ground-level ozone set the daily AQI on 58.1% of April days in Rockford. The highest April AQI recorded in 2019–2025 was 80 (Moderate), in 2020.

Rockford April air quality, year by year

Rockford April air quality by year (Rockford, IL, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193048075O3
2020worst3048074PM2.5
20213044080O3
2022cleanest3041064O3
20233046067O3
20243043051O3
20253041064O3

What April air means in Rockford

A typical April day in Rockford 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 April days reached AQI 101+ in 2019–2025.

April's median AQI of 44 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 April AQI across every EPA metro area (100,677 metro-days, 2019–2025) is 44, so Rockford runs in line with the national April norm; 0.0% of its April days topped AQI 100 versus 0.7% nationally (about the same).

April is part of Rockford's spring season (March, April, May); the spring 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.