Los Angeles Air Quality in Summer

Across 2019–2025, Los Angeles's summer (June–August) air quality had a median AQI of 119 (Unhealthy for Sensitive Groups) over 644 monitored days in the Los Angeles-Long Beach-Anaheim, CA area. 65.7% of summer days (423 of 644) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 89.8% of days. The cleanest summer on record here was 2023 (median AQI 112, 52 days above 100) and the worst was 2024 (median 145, 77 days above 100, peak AQI 230).

119
Median AQI
Unhealthy for Sensitive Groups
65.7%
Days above AQI 100
423 of 644 days
176
90th percentile AQI
worst 1 day in 10
250
Peak AQI
Very Unhealthy
O3
Main pollutant
89.8% of days
1.4%
Good days
9 of 644
  • Good: 1.4%
  • Moderate: 32.9%
  • Unhealthy for Sensitive Groups: 38.2%
  • Unhealthy or worse: 27.5%

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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QUICK ANSWER

How is the air in Los Angeles in summer?

Unhealthy for Sensitive Groups on a typical day: median AQI 119 across 2019–2025, with 65.7% of summer days above AQI 100. Ground-level ozone is the main driver.

  • 1.4% of summer days were Good (AQI 0–50), 32.9% Moderate (51–100).
  • 423 days of 644 reached AQI 101+; the summer peak was 250.
  • Cleanest month: June; worst month: July.

Frequently asked questions

What is the air quality like in Los Angeles in summer?

Across 2019–2025, the median daily AQI in Los Angeles in summer was 119 (Unhealthy for Sensitive Groups). 1.4% of days were Good, 32.9% Moderate, and 65.7% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.

Is summer a good time for outdoor exercise in Los Angeles?

A typical summer day in Los Angeles is already Unhealthy for Sensitive Groups (median AQI 119): people with asthma or heart disease, children and older adults should reduce prolonged outdoor exertion on most days, and about 66% of summer days (65.7%) were at that level or worse.

Which pollutant causes Los Angeles's summer air quality problems?

Ground-level ozone set the daily AQI on 89.8% of summer days in Los Angeles. The highest summer AQI recorded in 2019–2025 was 250 (Very Unhealthy), in 2024.

Los Angeles summer air quality, year by year

Los Angeles summer air quality by year (Los Angeles-Long Beach-Anaheim, CA, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
20199211960201O3
20209211560250O3
20219211757195O3
20229211259182O3
2023cleanest9211252210O3
2024worst9214577230O3
20259211958201O3

What summer air means in Los Angeles

A typical summer day in Los Angeles is already Unhealthy for Sensitive Groups (median AQI 119): people with asthma or heart disease, children and older adults should reduce prolonged outdoor exertion on most days, and about 66% of summer days (65.7%) were at that level or worse.

Summer's median AQI of 119 is above Los Angeles's whole-year median of 74, making it one of the area's dirtier periods. Nationally, the median Summer AQI across every EPA metro area (308,645 metro-days, 2019–2025) is 46, so Los Angeles runs above the national Summer norm; 65.7% of its Summer days topped AQI 100 versus 3.6% nationally (above average).

Within the season, June is the cleanest month (median AQI 100, 48.6% of days above 100) and July the worst (median 129, 76.1% above 100).

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 season 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.