Des Moines Air Quality in 2020

In 2020, Des Moines's air quality (Des Moines-West Des Moines, IA area) had a median daily AQI of 42 (Good) across 366 monitored days. 2 days (0.5%) reached Unhealthy for Sensitive Groups or worse, 261 were Good, and the year's peak AQI was 199 (Unhealthy). Fine particulate matter (PM2.5) set the daily AQI on 237 of those days. The cleanest month of 2020 was February (median AQI 34, 0 days above 100) and the worst was July (median 38, 2 days above 100, peak 199).

42
Median AQI
Good
2
Days above AQI 100
0.5% of 366 days
59
90th percentile AQI
worst 1 day in 10
199
Peak AQI
Unhealthy
PM2.5
Main pollutant
237 of 366 days
261
Good days
71.3% of days
  • Good: 71.3%
  • Moderate: 28.1%
  • Unhealthy for Sensitive Groups: 0.0%
  • Unhealthy or worse: 0.5%

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QUICK ANSWER

How was Des Moines's air quality in 2020?

Good on a typical day: median AQI 42, with 2 days above AQI 100 out of 366 monitored — the 5th cleanest of 7 years on record for the area.

  • Peak AQI in 2020: 199 (Unhealthy).
  • Fine particulate matter (PM2.5) was the main pollutant on 237 days.
  • Cleanest month: February; worst: July.

Frequently asked questions

What was the average AQI in Des Moines in 2020?

EPA's Air Quality System puts Des Moines's (Des Moines-West Des Moines, IA) median daily AQI for 2020 at 42, which is Good. 2 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 199.

Which month had the worst air quality in Des Moines in 2020?

The cleanest month of 2020 was February (median AQI 34, 0 days above 100) and the worst was July (median 38, 2 days above 100, peak 199).

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

Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 5th cleanest by days above AQI 100. 2020's median of 42 is in line with the area's typical annual median of 44.

Des Moines month by month in 2020

Des Moines air quality month by month, 2020 (Des Moines-West Des Moines, IA, EPA AQS daily AQI)

MonthDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
January3149068PM2.5
Februarycleanest2934058PM2.5
March3137066O3
April3044064O3
May3139049O3
June3054084O3
Julyworst31382199O3
August3141061PM2.5
September3034056O3
October3137060PM2.5
November3038061PM2.5
December3152076PM2.5

How 2020 compares

Among the 7 years EPA has published for the area (2019–2025), 2020 ranks 5th cleanest by days above AQI 100.

2020's median of 42 is in line with the area's typical annual median of 44.

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

Right now in Des Moines

The latest EPA AirNow observation puts Des Moines's AQI at 37 (PM2.5). The figures above are multi-year annual statistics, not today's reading.

View current Des Moines air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Des Moines-West Des Moines, IA), 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.