Des Moines Air Quality in 2021
In 2021, Des Moines's air quality (Des Moines-West Des Moines, IA area) had a median daily AQI of 45 (Good) across 365 monitored days. 1 day (0.3%) reached Unhealthy for Sensitive Groups or worse, 227 were Good, and the year's peak AQI was 110 (Unhealthy for Sensitive Groups). Fine particulate matter (PM2.5) set the daily AQI on 243 of those days. The cleanest month of 2021 was November (median AQI 33, 0 days above 100) and the worst was August (median 54, 1 day above 100, peak 110).
- Good: 62.2%
- Moderate: 37.5%
- Unhealthy for Sensitive Groups: 0.3%
- Unhealthy or worse: 0.0%
Improve Indoor Air Quality
Even with good outdoor air in Des Moines, indoor PM2.5, dust and allergens build up. A True-HEPA purifier keeps a bedroom or office consistently clean.
Recommended: Levoit Core 400S — True HEPA · CADR ~141 CFM · rooms up to 219 sq ft
As an Amazon Associate, we earn from qualifying purchases.
How was Des Moines's air quality in 2021?
Good on a typical day: median AQI 45, with 1 day above AQI 100 out of 365 monitored — the 4th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2021: 110 (Unhealthy for Sensitive Groups).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 243 days.
- ✓Cleanest month: November; worst: August.
Frequently asked questions
What was the average AQI in Des Moines in 2021?▾
EPA's Air Quality System puts Des Moines's (Des Moines-West Des Moines, IA) median daily AQI for 2021 at 45, which is Good. 1 day were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 110.
Which month had the worst air quality in Des Moines in 2021?▾
The cleanest month of 2021 was November (median AQI 33, 0 days above 100) and the worst was August (median 54, 1 day above 100, peak 110).
Was 2021 a good or bad year for Des Moines's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 4th cleanest by days above AQI 100. 2021's median of 45 is in line with the area's typical annual median of 44.
Des Moines month by month in 2021
Des Moines air quality month by month, 2021 (Des Moines-West Des Moines, IA, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 48 | 0 | 84 | PM2.5 |
| February | 28 | 50 | 0 | 80 | PM2.5 |
| March | 31 | 48 | 0 | 74 | PM2.5 |
| April | 30 | 45 | 0 | 71 | O3 |
| May | 31 | 41 | 0 | 54 | O3 |
| June | 30 | 48 | 0 | 84 | O3 |
| July | 31 | 60 | 0 | 88 | PM2.5 |
| Augustworst | 31 | 54 | 1 | 110 | PM2.5 |
| September | 30 | 44 | 0 | 74 | O3 |
| October | 31 | 37 | 0 | 57 | PM2.5 |
| Novembercleanest | 30 | 33 | 0 | 77 | PM2.5 |
| December | 31 | 44 | 0 | 64 | PM2.5 |
How 2021 compares
Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 4th cleanest by days above AQI 100.
2021's median of 45 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.