Santa Rosa Air Quality in April

Across 2019–2025, Santa Rosa's April air quality had a median AQI of 33 (Good) over 210 monitored days in the Santa Rosa, CA 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 54.3% of days. The cleanest April on record here was 2025 (median AQI 9, 0 days above 100) and the worst was 2022 (median 39, 0 days above 100, peak AQI 52).

33
Median AQI
Good
0.0%
Days above AQI 100
0 of 210 days
43
90th percentile AQI
worst 1 day in 10
60
Peak AQI
Moderate
O3
Main pollutant
54.3% of days
92.9%
Good days
195 of 210
  • Good: 92.9%
  • Moderate: 7.1%
  • Unhealthy for Sensitive Groups: 0.0%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How is the air in Santa Rosa in April?

Good on a typical day: median AQI 33 across 2019–2025, with 0.0% of April days above AQI 100. Ground-level ozone is the main driver.

  • 92.9% of April days were Good (AQI 0–50), 7.1% Moderate (51–100).
  • 0 days of 210 reached AQI 101+; the April peak was 60.
  • Best April: 2025; worst April: 2022.

Frequently asked questions

What is the air quality like in Santa Rosa in April?

Across 2019–2025, the median daily AQI in Santa Rosa in April was 33 (Good). 92.9% of days were Good, 7.1% 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 Santa Rosa?

A typical April day in Santa Rosa sits in the Good range (median AQI 33), 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 Santa Rosa's April air quality problems?

Ground-level ozone set the daily AQI on 54.3% of April days in Santa Rosa. The highest April AQI recorded in 2019–2025 was 60 (Moderate), in 2022.

Santa Rosa April air quality, year by year

Santa Rosa April air quality by year (Santa Rosa, CA, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20193035060O3
20203032046O3
20213039058PM2.5
2022worst3039052O3
20233037043O3
20243017038PM2.5
2025cleanest309028PM10

What April air means in Santa Rosa

A typical April day in Santa Rosa sits in the Good range (median AQI 33), 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 33 is in line with Santa Rosa's whole-year median of 36, 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 Santa Rosa runs below the national April norm; 0.0% of its April days topped AQI 100 versus 0.7% nationally (about the same).

April is part of Santa Rosa's spring season (March, April, May); the spring page pools all three months.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Santa Rosa

The latest EPA AirNow observation puts Santa Rosa's AQI at 36 (PM2.5). The figures above are multi-year month statistics, not today's reading.

View current Santa Rosa air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Santa Rosa, CA), 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.