State air quality · 2025
South Dakota Air Quality Ranking
Across 10 monitored counties, the typical county in South Dakota posts a median AQI of 35 (Good) and 80.8% of monitored days were rated Good, from EPA AQS.
- 35
- Avg median AQI
- 80.8%
- Good-air days
- 10
- Counties monitored
- 67%
- Cleaner than US states
South Dakota's typical county median AQI is 35 (Good) across 10 monitored counties
According to the U.S. EPA Air Quality System, South Dakota monitors 10 counties with a day-weighted Good-day share of 80.8%. Cleanest: Meade County (97.4% Good). Most polluted: Brookings County (58.6%). These are annual summaries, not live AirNow readings.
Data source EPA Air Quality System (AQS)
- Cleaner than US states
- South Dakota's day-weighted Good-day share of 80.8% places it cleaner than 67% of US states.
- In-state spread
- Within South Dakota, Meade County leads at 97.4% Good days while Brookings County sits at 58.6% across 10 monitored counties.
- 2024→2025 release
- South Dakota's Good-day share moved +2.5 points vs the 2024 EPA annual release.
- Typical median AQI
- Typical median AQI: 35
Verify with AirNow → · EPA AQS →
EPA state monitoring brief
AQS state key SOUTH-DAKOTA
South Dakota · 2025 EPA AQS · 10 counties · med AQI 35 · 80.8% Good · Meade→Brookings spread
- GOOD 35 Median AQI · Good
- SHARE 80.8% Good-day share
- COUNT 10 Counties monitored
- UNH 2 Unhealthy+ days
- RANK 67% Cleaner than states
- PM25 52.7% Main pollutant share
Good-day share peers
South Dakota's 80.8% Good-day share is cleaner than 67% of monitored US states; Meade and Brookings County bracket the in-state range. Open Meade County →
According to EPA AQS annual summaries on PlainAirData, South Dakota ranks #17 of 52 by day-weighted good-day share (80.8%) and #14 by mean county median AQI (35.2). Hawaii is #1 of 52 by day-weighted good-day share (93.8% of monitored days) at mean county median-AQI #4 (27.3) ≠ Alaska #1 lowest mean county median AQI (20.3) at good-day share #8 (84.4%).
Data updated August 2026
What changed, what drives it, and how thick is the sample
Three derived views WPR-style word count does not substitute for: release-over-release movement from county annual rows, the EPA main-pollutant day mix, and how many counties sit below the 100-day ranking floor.
Release change
80.8%
Good-day share in 2025, up 2.5 percentage points vs 2024. County-mean median AQI 35, within half a point of the 2024 county-mean median.
Pollutant mix
PM2.5
Main driver on 52.7% of pollutant-assigned days.
- PM2.5 52.7%
- Ozone 39.4%
- PM10 7.7%
- NO2 0.2%
Monitoring coverage
360
Average monitored days per county in the latest release. Every monitored county clears the 100-day ranking floor.
Counties Monitored
10
Good Days %
80.8%
Avg Median AQI
35
Total Unhealthy Days
2
Best Air Quality
Meade County
Worst Air Quality
Brookings County
Where South Dakota sits nationally
COUNT-derived placement among 52 US states with at least 365 monitored days in the latest county release. South Dakota's day-weighted Good-day share is 80.8% - cleaner than 67% of that comparison set.
South Dakota Good-day share vs. every US state
Day-weighted share of monitored days in the Good band (AQI 0–50) - EPA AQS annual release
80.8% Cleaner than 67% higher than 67% of 52 US states
Each bar is a band; taller bars hold more US states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source U.S. Environmental Protection Agency, Air Quality System (AQS) · 2025
Which counties in South Dakota have the cleanest and most polluted air?
Cleanest counties in South Dakota
Data Sources
Primary Source: U.S. Environmental Protection Agency (EPA), Air Quality System (AQS), Annual AQI by County dataset, 2020–2025. See our methodology for how AQI and median figures are computed.
Coverage: 10 counties in South Dakota with active monitoring stations. Unmonitored counties are not represented.
Source: U.S. EPA Air Quality System (AQS) Annual AQI by county summary files, aggregated to the state level · 2020–2025
Every figure on PlainAirData is rendered directly from EPA AQS air-quality monitoring data, no number is typed in by an editor. This page draws directly on EPA AQS air-quality monitoring data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.
Informational only, not professional advice. Data from EPA AQS. See our disclaimer.