Aurora, CO Air Quality in 2020

In 2020, Aurora's air quality (Denver-Aurora-Lakewood, CO area) had a median daily AQI of 62 (Moderate) across 366 monitored days. 35 days (9.6%) reached Unhealthy for Sensitive Groups or worse, 61 were Good, and the year's peak AQI was 161 (Unhealthy). Ground-level ozone set the daily AQI on 217 of those days. The cleanest month of 2020 was November (median AQI 53, 0 days above 100) and the worst was August (median 105, 17 days above 100, peak 161).

62
Median AQI
Moderate
35
Days above AQI 100
9.6% of 366 days
99
90th percentile AQI
worst 1 day in 10
161
Peak AQI
Unhealthy
O3
Main pollutant
217 of 366 days
61
Good days
16.7% of days
  • Good: 16.7%
  • Moderate: 73.8%
  • Unhealthy for Sensitive Groups: 8.5%
  • Unhealthy or worse: 1.1%

Reduce Indoor Ozone in Aurora

Today's main pollutant in Aurora is ground-level ozone (AQI 48). 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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QUICK ANSWER

How was Aurora's air quality in 2020?

Moderate on a typical day: median AQI 62, with 35 days above AQI 100 out of 366 monitored — the 4th cleanest of 7 years on record for the area.

  • Peak AQI in 2020: 161 (Unhealthy).
  • Ground-level ozone was the main pollutant on 217 days.
  • Cleanest month: November; worst: August.

Frequently asked questions

What was the average AQI in Aurora in 2020?

EPA's Air Quality System puts Aurora's (Denver-Aurora-Lakewood, CO) median daily AQI for 2020 at 62, which is Moderate. 35 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 161.

Which month had the worst air quality in Aurora in 2020?

The cleanest month of 2020 was November (median AQI 53, 0 days above 100) and the worst was August (median 105, 17 days above 100, peak 161).

Was 2020 a good or bad year for Aurora's air?

Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 4th cleanest by days above AQI 100. 2020's median of 62 is in line with the area's typical annual median of 64.

Aurora month by month in 2020

Aurora air quality month by month, 2020 (Denver-Aurora-Lakewood, CO, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January31541103NO2
February2957089O3
March3157080O3
April3061087O3
May31741105O3
June30693147O3
July31745147O3
Augustworst3110517161O3
September30796136O3
October31642143PM2.5
Novembercleanest3053077NO2
December3153093PM2.5

How 2020 compares

Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 4th cleanest by days above AQI 100.

2020's median of 62 is in line with the area's typical annual median of 64.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in Aurora

The latest EPA AirNow observation puts Aurora's AQI at 48 (O3). The figures above are multi-year annual 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.