Las Vegas Air Quality in December
Across 2019–2025, Las Vegas's December air quality had a median AQI of 68 (Moderate) over 217 monitored days in the Las Vegas-Henderson-Paradise, NV area. 5.0% of December days (11 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 83.4% of days. The cleanest December on record here was 2025 (median AQI 76, 0 days above 100) and the worst was 2020 (median 71, 5 days above 100, peak AQI 158).
- Good: 20.7%
- Moderate: 74.2%
- Unhealthy for Sensitive Groups: 4.1%
- Unhealthy or worse: 0.9%
Reduce Indoor Ozone in Las Vegas
Today's main pollutant in Las Vegas is ground-level ozone (AQI 31). 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 Las Vegas in December?
Moderate on a typical day: median AQI 68 across 2019–2025, with 5.0% of December days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓20.7% of December days were Good (AQI 0–50), 74.2% Moderate (51–100).
- ✓11 days of 217 reached AQI 101+; the December peak was 158.
- ✓Best December: 2025; worst December: 2020.
Frequently asked questions
What is the air quality like in Las Vegas in December?▾
Across 2019–2025, the median daily AQI in Las Vegas in December was 68 (Moderate). 20.7% of days were Good, 74.2% Moderate, and 5.0% 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 Las Vegas?▾
A typical December day in Las Vegas is Moderate (median AQI 68): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 20 of December days (5.0%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Las Vegas's December air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 83.4% of December days in Las Vegas. The highest December AQI recorded in 2019–2025 was 158 (Unhealthy), in 2020.
Las Vegas December air quality, year by year
Las Vegas December air quality by year (Las Vegas-Henderson-Paradise, NV, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 60 | 1 | 102 | PM2.5 |
| 2020worst | 31 | 71 | 5 | 158 | PM2.5 |
| 2021 | 31 | 57 | 1 | 104 | PM2.5 |
| 2022 | 31 | 62 | 2 | 152 | PM2.5 |
| 2023 | 31 | 72 | 1 | 129 | PM2.5 |
| 2024 | 31 | 73 | 1 | 101 | PM2.5 |
| 2025cleanest | 31 | 76 | 0 | 95 | PM2.5 |
What December air means in Las Vegas
A typical December day in Las Vegas is Moderate (median AQI 68): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 20 of December days (5.0%) 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 68 is above Las Vegas's whole-year median of 62, making it one of the area's dirtier periods. Nationally, the median December AQI across every EPA metro area (95,590 metro-days, 2019–2025) is 39, so Las Vegas runs above the national December norm; 5.0% of its December days topped AQI 100 versus 0.7% nationally (above average).
December is part of Las Vegas's winter season (December, January, February); the winter page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Las Vegas
The latest EPA AirNow observation puts Las Vegas's AQI at 31 (O3). The figures above are multi-year month statistics, not today's reading.
View current Las Vegas air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Las Vegas-Henderson-Paradise, NV), 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.