Sioux Falls Air Quality in May
Across 2019–2025, Sioux Falls's May air quality had a median AQI of 44 (Good) over 217 monitored days in the Sioux Falls, SD area. 4.2% of May days (9 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 79.3% of days. The cleanest May on record here was 2020 (median AQI 38, 0 days above 100) and the worst was 2023 (median 67, 9 days above 100, peak AQI 181).
- Good: 71.9%
- Moderate: 24.0%
- Unhealthy for Sensitive Groups: 3.7%
- Unhealthy or worse: 0.5%
Reduce Indoor Ozone in Sioux Falls
Today's main pollutant in Sioux Falls is ground-level ozone (AQI 24). 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 Sioux Falls in May?
Good on a typical day: median AQI 44 across 2019–2025, with 4.2% of May days above AQI 100. Ground-level ozone is the main driver.
- ✓71.9% of May days were Good (AQI 0–50), 24.0% Moderate (51–100).
- ✓9 days of 217 reached AQI 101+; the May peak was 181.
- ✓Best May: 2020; worst May: 2023.
Frequently asked questions
What is the air quality like in Sioux Falls in May?▾
Across 2019–2025, the median daily AQI in Sioux Falls in May was 44 (Good). 71.9% of days were Good, 24.0% Moderate, and 4.2% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is May a good time for outdoor exercise in Sioux Falls?▾
A typical May day in Sioux Falls sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 24 of May days (4.2%) reached AQI 101+ in 2019–2025.
Which pollutant causes Sioux Falls's May air quality problems?▾
Ground-level ozone set the daily AQI on 79.3% of May days in Sioux Falls. The highest May AQI recorded in 2019–2025 was 181 (Unhealthy), in 2023.
Sioux Falls May air quality, year by year
Sioux Falls May air quality by year (Sioux Falls, SD, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 40 | 0 | 77 | O3 |
| 2020cleanest | 31 | 38 | 0 | 61 | PM2.5 |
| 2021 | 31 | 42 | 0 | 64 | O3 |
| 2022 | 31 | 44 | 0 | 80 | O3 |
| 2023worst | 31 | 67 | 9 | 181 | O3 |
| 2024 | 31 | 44 | 0 | 81 | O3 |
| 2025 | 31 | 40 | 0 | 80 | O3 |
What May air means in Sioux Falls
A typical May day in Sioux Falls sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; about 1 day in 24 of May days (4.2%) reached AQI 101+ in 2019–2025.
May's median AQI of 44 is above Sioux Falls's whole-year median of 38, making it one of the area's dirtier periods. Nationally, the median May AQI across every EPA metro area (104,064 metro-days, 2019–2025) is 44, so Sioux Falls runs in line with the national May norm; 4.2% of its May days topped AQI 100 versus 1.3% nationally (above average).
May is part of Sioux Falls's spring season (March, April, May); the spring page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Sioux Falls
The latest EPA AirNow observation puts Sioux Falls's AQI at 24 (O3). The figures above are multi-year month statistics, not today's reading.
View current Sioux Falls air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Sioux Falls, SD), 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.