Los Angeles Air Quality in May
Across 2019–2025, Los Angeles's May air quality had a median AQI of 74 (Moderate) over 217 monitored days in the Los Angeles-Long Beach-Anaheim, CA area. 22.2% of May days (48 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 68.2% of days. The cleanest May on record here was 2019 (median AQI 56, 1 day above 100) and the worst was 2020 (median 90, 12 days above 100, peak AQI 206).
- Good: 10.6%
- Moderate: 67.3%
- Unhealthy for Sensitive Groups: 17.1%
- Unhealthy or worse: 5.1%
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 May?
Moderate on a typical day: median AQI 74 across 2019–2025, with 22.2% of May days above AQI 100. Ground-level ozone is the main driver.
- ✓10.6% of May days were Good (AQI 0–50), 67.3% Moderate (51–100).
- ✓48 days of 217 reached AQI 101+; the May peak was 206.
- ✓Best May: 2019; worst May: 2020.
Frequently asked questions
What is the air quality like in Los Angeles in May?▾
Across 2019–2025, the median daily AQI in Los Angeles in May was 74 (Moderate). 10.6% of days were Good, 67.3% Moderate, and 22.2% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is May a good time for outdoor exercise in Los Angeles?▾
A typical May day in Los Angeles 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 5 of May days (22.2%) 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 May air quality problems?▾
Ground-level ozone set the daily AQI on 68.2% of May days in Los Angeles. The highest May AQI recorded in 2019–2025 was 206 (Very Unhealthy), in 2020.
Los Angeles May air quality, year by year
Los Angeles May 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 |
|---|---|---|---|---|---|
| 2019cleanest | 31 | 56 | 1 | 105 | PM2.5 |
| 2020worst | 31 | 90 | 12 | 206 | O3 |
| 2021 | 31 | 80 | 3 | 129 | O3 |
| 2022 | 31 | 80 | 9 | 192 | O3 |
| 2023 | 31 | 53 | 7 | 136 | O3 |
| 2024 | 31 | 77 | 4 | 119 | O3 |
| 2025 | 31 | 74 | 12 | 159 | O3 |
What May air means in Los Angeles
A typical May day in Los Angeles 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 5 of May days (22.2%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
May's median AQI of 74 is in line with Los Angeles's whole-year median of 74, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median May AQI across every EPA metro area (104,064 metro-days, 2019–2025) is 44, so Los Angeles runs above the national May norm; 22.2% of its May days topped AQI 100 versus 1.3% nationally (above average).
May is part of Los Angeles's spring season (March, April, May); the spring 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.