Aurora, CO Air Quality in August
Across 2019–2025, Aurora's August air quality had a median AQI of 87 (Moderate) over 217 monitored days in the Denver-Aurora-Lakewood, CO area. 33.6% of August days (73 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 94.0% of days. The cleanest August on record here was 2025 (median AQI 68, 2 days above 100) and the worst was 2021 (median 115, 20 days above 100, peak AQI 158).
- Good: 3.7%
- Moderate: 62.7%
- Unhealthy for Sensitive Groups: 29.0%
- Unhealthy or worse: 4.6%
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 August?
Moderate on a typical day: median AQI 87 across 2019–2025, with 33.6% of August days above AQI 100. Ground-level ozone is the main driver.
- ✓3.7% of August days were Good (AQI 0–50), 62.7% Moderate (51–100).
- ✓73 days of 217 reached AQI 101+; the August peak was 161.
- ✓Best August: 2025; worst August: 2021.
Frequently asked questions
What is the air quality like in Aurora in August?▾
Across 2019–2025, the median daily AQI in Aurora in August was 87 (Moderate). 3.7% of days were Good, 62.7% Moderate, and 33.6% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is August a good time for outdoor exercise in Aurora?▾
A typical August day in Aurora is Moderate (median AQI 87): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 3 of August days (33.6%) 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 August air quality problems?▾
Ground-level ozone set the daily AQI on 94.0% of August days in Aurora. The highest August AQI recorded in 2019–2025 was 161 (Unhealthy), in 2021.
Aurora August air quality, year by year
Aurora August 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 | 87 | 8 | 154 | O3 |
| 2020 | 31 | 105 | 17 | 161 | O3 |
| 2021worst | 31 | 115 | 20 | 158 | O3 |
| 2022 | 31 | 97 | 11 | 133 | O3 |
| 2023 | 31 | 84 | 8 | 143 | O3 |
| 2024 | 31 | 84 | 7 | 161 | O3 |
| 2025cleanest | 31 | 68 | 2 | 119 | O3 |
What August air means in Aurora
A typical August day in Aurora is Moderate (median AQI 87): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 3 of August days (33.6%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
August's median AQI of 87 is above Aurora's whole-year median of 64, making it one of the area's dirtier periods. Nationally, the median August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so Aurora runs above the national August norm; 33.6% of its August days topped AQI 100 versus 3.5% nationally (above average).
August is part of Aurora's summer season (June, July, August); the summer 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.