Denver Air Quality in February
Across 2019–2025, Denver's February air quality had a median AQI of 57 (Moderate) over 198 monitored days in the Denver-Aurora-Lakewood, CO area. 0.0% of February days (0 of 198) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 40.9% of days. The cleanest February on record here was 2022 (median AQI 54, 0 days above 100) and the worst was 2019 (median 63, 0 days above 100, peak AQI 99).
- Good: 30.3%
- Moderate: 69.7%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
Reduce Indoor Ozone in Denver
Today's main pollutant in Denver is ground-level ozone (AQI 43). 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 Denver in February?
Moderate on a typical day: median AQI 57 across 2019–2025, with 0.0% of February days above AQI 100. Ground-level ozone is the main driver.
- ✓30.3% of February days were Good (AQI 0–50), 69.7% Moderate (51–100).
- ✓0 days of 198 reached AQI 101+; the February peak was 99.
- ✓Best February: 2022; worst February: 2019.
Frequently asked questions
What is the air quality like in Denver in February?▾
Across 2019–2025, the median daily AQI in Denver in February was 57 (Moderate). 30.3% of days were Good, 69.7% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 198 monitored days in EPA's Air Quality System.
Is February a good time for outdoor exercise in Denver?▾
A typical February day in Denver is Moderate (median AQI 57): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of February days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Denver's February air quality problems?▾
Ground-level ozone set the daily AQI on 40.9% of February days in Denver. The highest February AQI recorded in 2019–2025 was 99 (Moderate), in 2019.
Denver February air quality, year by year
Denver February air quality by year (Denver-Aurora-Lakewood, CO, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019worst | 28 | 63 | 0 | 99 | PM2.5 |
| 2020 | 29 | 57 | 0 | 89 | O3 |
| 2021 | 28 | 56 | 0 | 85 | PM2.5 |
| 2022cleanest | 28 | 54 | 0 | 84 | O3 |
| 2023 | 28 | 54 | 0 | 76 | O3 |
| 2024 | 29 | 54 | 0 | 77 | O3 |
| 2025 | 28 | 60 | 0 | 86 | O3 |
What February air means in Denver
A typical February day in Denver is Moderate (median AQI 57): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of February days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
February's median AQI of 57 is below Denver's whole-year median of 64, making it one of the area's cleaner periods. Nationally, the median February AQI across every EPA metro area (87,428 metro-days, 2019–2025) is 41, so Denver runs above the national February norm; 0.0% of its February days topped AQI 100 versus 0.4% nationally (about the same).
February is part of Denver's winter season (December, January, February); the winter page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Denver
The latest EPA AirNow observation puts Denver's AQI at 43 (O3). The figures above are multi-year month statistics, not today's reading.
View current Denver air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Denver-Aurora-Lakewood, CO), 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.