Los Angeles Air Quality in October
Across 2019–2025, Los Angeles's October air quality had a median AQI of 80 (Moderate) over 217 monitored days in the Los Angeles-Long Beach-Anaheim, CA area. 27.7% of October days (60 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 52.5% of days. The cleanest October on record here was 2025 (median AQI 69, 0 days above 100) and the worst was 2020 (median 129, 21 days above 100, peak AQI 210).
- Good: 4.1%
- Moderate: 68.2%
- Unhealthy for Sensitive Groups: 15.7%
- Unhealthy or worse: 12.0%
Reduce Indoor Ozone in Los Angeles
Today's main pollutant in Los Angeles is ground-level ozone (AQI 38). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Los Angeles in October?
Moderate on a typical day: median AQI 80 across 2019–2025, with 27.7% of October days above AQI 100. Ground-level ozone is the main driver.
- ✓4.1% of October days were Good (AQI 0–50), 68.2% Moderate (51–100).
- ✓60 days of 217 reached AQI 101+; the October peak was 281.
- ✓Best October: 2025; worst October: 2020.
Frequently asked questions
What is the air quality like in Los Angeles in October?▾
Across 2019–2025, the median daily AQI in Los Angeles in October was 80 (Moderate). 4.1% of days were Good, 68.2% Moderate, and 27.7% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is October a good time for outdoor exercise in Los Angeles?▾
A typical October day in Los Angeles is Moderate (median AQI 80): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 4 of October days (27.7%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Los Angeles's October air quality problems?▾
Ground-level ozone set the daily AQI on 52.5% of October days in Los Angeles. The highest October AQI recorded in 2019–2025 was 281 (Very Unhealthy), in 2020.
Los Angeles October air quality, year by year
Los Angeles October air quality by year (Los Angeles-Long Beach-Anaheim, CA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 87 | 7 | 197 | O3 |
| 2020worst | 31 | 129 | 21 | 210 | O3 |
| 2021 | 31 | 66 | 3 | 281 | PM2.5 |
| 2022 | 31 | 71 | 5 | 143 | O3 |
| 2023 | 31 | 66 | 8 | 172 | O3 |
| 2024 | 31 | 101 | 16 | 203 | O3 |
| 2025cleanest | 31 | 69 | 0 | 100 | O3 |
What October air means in Los Angeles
A typical October day in Los Angeles is Moderate (median AQI 80): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 4 of October days (27.7%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
October's median AQI of 80 is above Los Angeles's whole-year median of 74, making it one of the area's dirtier periods. Nationally, the median October AQI across every EPA metro area (102,872 metro-days, 2019–2025) is 38, so Los Angeles runs above the national October norm; 27.7% of its October days topped AQI 100 versus 1.3% nationally (above average).
October is part of Los Angeles's fall season (September, October, November); the fall page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Los Angeles
The latest EPA AirNow observation puts Los Angeles's AQI at 38 (O3). The figures above are multi-year month statistics, not today's reading.
View current Los Angeles air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Los Angeles-Long Beach-Anaheim, 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.