Santa Rosa Air Quality in Summer
Across 2019–2025, Santa Rosa's summer (June–August) air quality had a median AQI of 25 (Good) over 644 monitored days in the Santa Rosa, CA area. 0.0% of summer days (0 of 644) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 39.3% of days. The cleanest summer on record here was 2025 (median AQI 11, 0 days above 100) and the worst was 2019 (median 36, 0 days above 100, peak AQI 87).
- Good: 88.8%
- Moderate: 11.2%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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How is the air in Santa Rosa in summer?
Good on a typical day: median AQI 25 across 2019–2025, with 0.0% of summer days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓88.8% of summer days were Good (AQI 0–50), 11.2% Moderate (51–100).
- ✓0 days of 644 reached AQI 101+; the summer peak was 97.
- ✓Cleanest month: July; worst month: June.
Frequently asked questions
What is the air quality like in Santa Rosa in summer?▾
Across 2019–2025, the median daily AQI in Santa Rosa in summer was 25 (Good). 88.8% of days were Good, 11.2% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is summer a good time for outdoor exercise in Santa Rosa?▾
A typical summer day in Santa Rosa sits in the Good range (median AQI 25), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of summer days reached AQI 101+ in 2019–2025.
Which pollutant causes Santa Rosa's summer air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 39.3% of summer days in Santa Rosa. The highest summer AQI recorded in 2019–2025 was 97 (Moderate), in 2019.
Santa Rosa summer air quality, year by year
Santa Rosa summer air quality by year (Santa Rosa, CA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019worst | 92 | 36 | 0 | 87 | PM2.5 |
| 2020 | 92 | 33 | 0 | 97 | PM2.5 |
| 2021 | 92 | 29 | 0 | 89 | O3 |
| 2022 | 92 | 24 | 0 | 57 | O3 |
| 2023 | 92 | 26 | 0 | 85 | O3 |
| 2024 | 92 | 18 | 0 | 64 | PM10 |
| 2025cleanest | 92 | 11 | 0 | 31 | PM10 |
What summer air means in Santa Rosa
A typical summer day in Santa Rosa sits in the Good range (median AQI 25), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of summer days reached AQI 101+ in 2019–2025.
Summer's median AQI of 25 is below Santa Rosa's whole-year median of 36, making it one of the area's cleaner periods. Nationally, the median Summer AQI across every EPA metro area (308,645 metro-days, 2019–2025) is 46, so Santa Rosa runs below the national Summer norm; 0.0% of its Summer days topped AQI 100 versus 3.6% nationally (below average).
Within the season, July is the cleanest month (median AQI 23, 0.0% of days above 100) and June the worst (median 28, 0.0% above 100).
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 season 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.