Santa Rosa Air Quality in August
Across 2019–2025, Santa Rosa's August air quality had a median AQI of 24 (Good) over 217 monitored days in the Santa Rosa, CA area. 0.0% of August days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 41.9% of days. The cleanest August on record here was 2024 (median AQI 11, 0 days above 100) and the worst was 2020 (median 40, 0 days above 100, peak AQI 97).
- Good: 80.6%
- Moderate: 19.4%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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How is the air in Santa Rosa in August?
Good on a typical day: median AQI 24 across 2019–2025, with 0.0% of August days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓80.6% of August days were Good (AQI 0–50), 19.4% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the August peak was 97.
- ✓Best August: 2024; worst August: 2020.
Frequently asked questions
What is the air quality like in Santa Rosa in August?▾
Across 2019–2025, the median daily AQI in Santa Rosa in August was 24 (Good). 80.6% of days were Good, 19.4% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is August a good time for outdoor exercise in Santa Rosa?▾
A typical August day in Santa Rosa sits in the Good range (median AQI 24), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of August days reached AQI 101+ in 2019–2025.
Which pollutant causes Santa Rosa's August air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 41.9% of August days in Santa Rosa. The highest August AQI recorded in 2019–2025 was 97 (Moderate), in 2020.
Santa Rosa August air quality, year by year
Santa Rosa August 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 | 35 | 0 | 57 | PM2.5 |
| 2020worst | 31 | 40 | 0 | 97 | PM2.5 |
| 2021 | 31 | 31 | 0 | 89 | PM2.5 |
| 2022 | 31 | 22 | 0 | 57 | O3 |
| 2023 | 31 | 26 | 0 | 85 | O3 |
| 2024cleanest | 31 | 11 | 0 | 38 | PM10 |
| 2025 | 31 | 11 | 0 | 19 | PM10 |
What August air means in Santa Rosa
A typical August day in Santa Rosa sits in the Good range (median AQI 24), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of August days reached AQI 101+ in 2019–2025.
August's median AQI of 24 is below Santa Rosa's whole-year median of 36, making it one of the area's cleaner periods. Nationally, the median August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so Santa Rosa runs below the national August norm; 0.0% of its August days topped AQI 100 versus 3.5% nationally (below average).
August is part of Santa Rosa's summer season (June, July, August); the summer 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.