Los Angeles Air Quality in January
Across 2019–2025, Los Angeles's January air quality had a median AQI of 69 (Moderate) over 217 monitored days in the Los Angeles-Long Beach-Anaheim, CA area. 7.8% of January days (17 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 90.8% of days. The cleanest January on record here was 2023 (median AQI 64, 0 days above 100) and the worst was 2025 (median 71, 7 days above 100, peak AQI 182).
- Good: 6.5%
- Moderate: 85.7%
- Unhealthy for Sensitive Groups: 5.5%
- Unhealthy or worse: 2.3%
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.
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How is the air in Los Angeles in January?
Moderate on a typical day: median AQI 69 across 2019–2025, with 7.8% of January days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓6.5% of January days were Good (AQI 0–50), 85.7% Moderate (51–100).
- ✓17 days of 217 reached AQI 101+; the January peak was 184.
- ✓Best January: 2023; worst January: 2025.
Frequently asked questions
What is the air quality like in Los Angeles in January?▾
Across 2019–2025, the median daily AQI in Los Angeles in January was 69 (Moderate). 6.5% of days were Good, 85.7% Moderate, and 7.8% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is January a good time for outdoor exercise in Los Angeles?▾
A typical January day in Los Angeles is Moderate (median AQI 69): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 13 of January days (7.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Los Angeles's January air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 90.8% of January days in Los Angeles. The highest January AQI recorded in 2019–2025 was 184 (Unhealthy), in 2025.
Los Angeles January air quality, year by year
Los Angeles January 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 | 70 | 1 | 106 | PM2.5 |
| 2020 | 31 | 73 | 5 | 130 | PM2.5 |
| 2021 | 31 | 71 | 1 | 184 | PM2.5 |
| 2022 | 31 | 71 | 2 | 106 | PM2.5 |
| 2023cleanest | 31 | 64 | 0 | 82 | PM2.5 |
| 2024 | 31 | 67 | 1 | 104 | PM2.5 |
| 2025worst | 31 | 71 | 7 | 182 | PM2.5 |
What January air means in Los Angeles
A typical January day in Los Angeles is Moderate (median AQI 69): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 13 of January days (7.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
January's median AQI of 69 is below Los Angeles's whole-year median of 74, making it one of the area's cleaner periods. Nationally, the median January AQI across every EPA metro area (95,602 metro-days, 2019–2025) is 39, so Los Angeles runs above the national January norm; 7.8% of its January days topped AQI 100 versus 0.7% nationally (above average).
January is part of Los Angeles's winter season (December, January, February); the winter 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.