Long Beach Air Quality in December
Across 2019–2025, Long Beach's December air quality had a median AQI of 74 (Moderate) over 217 monitored days in the Los Angeles-Long Beach-Anaheim, CA area. 16.2% of December days (35 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 95.4% of days. The cleanest December on record here was 2019 (median AQI 66, 1 day above 100) and the worst was 2024 (median 82, 9 days above 100, peak AQI 155).
- Good: 4.6%
- Moderate: 79.3%
- Unhealthy for Sensitive Groups: 13.4%
- Unhealthy or worse: 2.8%
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How is the air in Long Beach in December?
Moderate on a typical day: median AQI 74 across 2019–2025, with 16.2% of December days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓4.6% of December days were Good (AQI 0–50), 79.3% Moderate (51–100).
- ✓35 days of 217 reached AQI 101+; the December peak was 155.
- ✓Best December: 2019; worst December: 2024.
Frequently asked questions
What is the air quality like in Long Beach in December?▾
Across 2019–2025, the median daily AQI in Long Beach in December was 74 (Moderate). 4.6% of days were Good, 79.3% Moderate, and 16.2% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is December a good time for outdoor exercise in Long Beach?▾
A typical December day in Long Beach 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 6 of December days (16.2%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Long Beach's December air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 95.4% of December days in Long Beach. The highest December AQI recorded in 2019–2025 was 155 (Unhealthy), in 2024.
Long Beach December air quality, year by year
Long Beach December 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 | 66 | 1 | 125 | PM2.5 |
| 2020 | 31 | 83 | 5 | 120 | PM2.5 |
| 2021 | 31 | 72 | 7 | 155 | PM2.5 |
| 2022 | 31 | 64 | 3 | 148 | PM2.5 |
| 2023 | 31 | 69 | 2 | 153 | PM2.5 |
| 2024worst | 31 | 82 | 9 | 155 | PM2.5 |
| 2025 | 31 | 80 | 8 | 152 | PM2.5 |
What December air means in Long Beach
A typical December day in Long Beach 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 6 of December days (16.2%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
December's median AQI of 74 is in line with Long Beach's whole-year median of 74, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median December AQI across every EPA metro area (95,590 metro-days, 2019–2025) is 39, so Long Beach runs above the national December norm; 16.2% of its December days topped AQI 100 versus 0.7% nationally (above average).
December is part of Long Beach's winter season (December, January, February); the winter page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Long Beach
The latest EPA AirNow observation puts Long Beach's AQI at 36 (PM2.5). The figures above are multi-year month statistics, not today's reading.
View current Long Beach 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.