Santa Rosa Air Quality in May
Across 2019–2025, Santa Rosa's May air quality had a median AQI of 31 (Good) over 217 monitored days in the Santa Rosa, CA area. 0.0% of May days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 53.0% of days. The cleanest May on record here was 2024 (median AQI 13, 0 days above 100) and the worst was 2022 (median 36, 0 days above 100, peak AQI 62).
- Good: 93.5%
- Moderate: 6.5%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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How is the air in Santa Rosa in May?
Good on a typical day: median AQI 31 across 2019–2025, with 0.0% of May days above AQI 100. Ground-level ozone is the main driver.
- ✓93.5% of May days were Good (AQI 0–50), 6.5% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the May peak was 62.
- ✓Best May: 2024; worst May: 2022.
Frequently asked questions
What is the air quality like in Santa Rosa in May?▾
Across 2019–2025, the median daily AQI in Santa Rosa in May was 31 (Good). 93.5% of days were Good, 6.5% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is May a good time for outdoor exercise in Santa Rosa?▾
A typical May day in Santa Rosa sits in the Good range (median AQI 31), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of May days reached AQI 101+ in 2019–2025.
Which pollutant causes Santa Rosa's May air quality problems?▾
Ground-level ozone set the daily AQI on 53.0% of May days in Santa Rosa. The highest May AQI recorded in 2019–2025 was 62 (Moderate), in 2022.
Santa Rosa May air quality, year by year
Santa Rosa May air quality by year (Santa Rosa, CA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 34 | 0 | 53 | O3 |
| 2020 | 31 | 33 | 0 | 44 | O3 |
| 2021 | 31 | 34 | 0 | 59 | O3 |
| 2022worst | 31 | 36 | 0 | 62 | O3 |
| 2023 | 31 | 31 | 0 | 57 | O3 |
| 2024cleanest | 31 | 13 | 0 | 60 | PM2.5 |
| 2025 | 31 | 13 | 0 | 23 | PM10 |
What May air means in Santa Rosa
A typical May day in Santa Rosa sits in the Good range (median AQI 31), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of May days reached AQI 101+ in 2019–2025.
May's median AQI of 31 is below Santa Rosa's whole-year median of 36, making it one of the area's cleaner periods. Nationally, the median May AQI across every EPA metro area (104,064 metro-days, 2019–2025) is 44, so Santa Rosa runs below the national May norm; 0.0% of its May days topped AQI 100 versus 1.3% nationally (below average).
May 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.