Aurora, CO Air Quality in March
Across 2019–2025, Aurora's March air quality had a median AQI of 58 (Moderate) over 217 monitored days in the Denver-Aurora-Lakewood, CO area. 1.9% of March days (4 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 63.6% of days. The cleanest March on record here was 2025 (median AQI 54, 0 days above 100) and the worst was 2021 (median 58, 2 days above 100, peak AQI 151).
- Good: 25.8%
- Moderate: 72.4%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 1.4%
Reduce Indoor Ozone in Aurora
Today's main pollutant in Aurora 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 Aurora in March?
Moderate on a typical day: median AQI 58 across 2019–2025, with 1.9% of March days above AQI 100. Ground-level ozone is the main driver.
- ✓25.8% of March days were Good (AQI 0–50), 72.4% Moderate (51–100).
- ✓4 days of 217 reached AQI 101+; the March peak was 190.
- ✓Best March: 2025; worst March: 2021.
Frequently asked questions
What is the air quality like in Aurora in March?▾
Across 2019–2025, the median daily AQI in Aurora in March was 58 (Moderate). 25.8% of days were Good, 72.4% Moderate, and 1.9% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is March a good time for outdoor exercise in Aurora?▾
A typical March day in Aurora is Moderate (median AQI 58): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 53 of March days (1.9%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Aurora's March air quality problems?▾
Ground-level ozone set the daily AQI on 63.6% of March days in Aurora. The highest March AQI recorded in 2019–2025 was 190 (Unhealthy), in 2021.
Aurora March air quality, year by year
Aurora March air quality by year (Denver-Aurora-Lakewood, CO, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 64 | 1 | 153 | O3 |
| 2020 | 31 | 57 | 0 | 80 | O3 |
| 2021worst | 31 | 58 | 2 | 151 | O3 |
| 2022 | 31 | 55 | 1 | 190 | O3 |
| 2023 | 31 | 59 | 0 | 77 | O3 |
| 2024 | 31 | 58 | 0 | 77 | O3 |
| 2025cleanest | 31 | 54 | 0 | 71 | O3 |
What March air means in Aurora
A typical March day in Aurora is Moderate (median AQI 58): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 53 of March days (1.9%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
March's median AQI of 58 is below Aurora's whole-year median of 64, making it one of the area's cleaner periods. Nationally, the median March AQI across every EPA metro area (102,455 metro-days, 2019–2025) is 42, so Aurora runs above the national March norm; 1.9% of its March days topped AQI 100 versus 0.4% nationally (above average).
March is part of Aurora's spring season (March, April, May); the spring page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Aurora
The latest EPA AirNow observation puts Aurora's AQI at 43 (O3). The figures above are multi-year month statistics, not today's reading.
View current Aurora 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.