Sacramento Air Quality in September
Across 2019–2025, Sacramento's September air quality had a median AQI of 74 (Moderate) over 210 monitored days in the Sacramento--Roseville--Arden-Arcade, CA area. 25.8% of September days (54 of 210) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 65.7% of days. The cleanest September on record here was 2025 (median AQI 54, 1 day above 100) and the worst was 2020 (median 138, 20 days above 100, peak AQI 243).
- Good: 21.9%
- Moderate: 52.4%
- Unhealthy for Sensitive Groups: 14.8%
- Unhealthy or worse: 11.0%
Improve Indoor Air Quality
Even with good outdoor air in Sacramento, indoor PM2.5, dust and allergens build up. A True-HEPA purifier keeps a bedroom or office consistently clean.
Recommended: Levoit Core 400S — True HEPA · CADR ~141 CFM · rooms up to 219 sq ft
As an Amazon Associate, we earn from qualifying purchases.
How is the air in Sacramento in September?
Moderate on a typical day: median AQI 74 across 2019–2025, with 25.8% of September days above AQI 100. Ground-level ozone is the main driver.
- ✓21.9% of September days were Good (AQI 0–50), 52.4% Moderate (51–100).
- ✓54 days of 210 reached AQI 101+; the September peak was 442.
- ✓Best September: 2025; worst September: 2020.
Frequently asked questions
What is the air quality like in Sacramento in September?▾
Across 2019–2025, the median daily AQI in Sacramento in September was 74 (Moderate). 21.9% of days were Good, 52.4% Moderate, and 25.8% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is September a good time for outdoor exercise in Sacramento?▾
A typical September day in Sacramento is Moderate (median AQI 74): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 4 of September days (25.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Sacramento's September air quality problems?▾
Ground-level ozone set the daily AQI on 65.7% of September days in Sacramento. The highest September AQI recorded in 2019–2025 was 442 (Hazardous), in 2020.
Sacramento September air quality, year by year
Sacramento September air quality by year (Sacramento--Roseville--Arden-Arcade, CA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 30 | 54 | 3 | 115 | O3 |
| 2020worst | 30 | 138 | 20 | 243 | PM2.5 |
| 2021 | 30 | 93 | 12 | 151 | O3 |
| 2022 | 30 | 82 | 13 | 442 | O3 |
| 2023 | 30 | 61 | 1 | 107 | O3 |
| 2024 | 30 | 61 | 4 | 133 | O3 |
| 2025cleanest | 30 | 54 | 1 | 119 | O3 |
What September air means in Sacramento
A typical September day in Sacramento is Moderate (median AQI 74): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 4 of September days (25.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
September's median AQI of 74 is above Sacramento's whole-year median of 58, making it one of the area's dirtier periods. Nationally, the median September AQI across every EPA metro area (100,699 metro-days, 2019–2025) is 43, so Sacramento runs above the national September norm; 25.8% of its September days topped AQI 100 versus 2.7% nationally (above average).
September is part of Sacramento's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Sacramento
The latest EPA AirNow observation puts Sacramento's AQI at 43 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Sacramento air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Sacramento--Roseville--Arden-Arcade, 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.