Bad Air Days in Hughes County, South Dakota: 1 a Year
1 bad air day a year
Fewer bad air days than most monitored US counties. Ranked 630 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly particles: smoke and dust (100% particle days).
The bad-air season here
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in July and September and May. Averaged over 2016 to 2025.
Is a purifier worth it here?
- Bad air days are rare here. A standard furnace filter is enough; no purifier needed for outdoor air.
- On the odd bad day, check AirNow and keep windows shut.
Better or worse than it was
The worst recent year was 2023, with 8 bad days on 359 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2021-07-30 | 268 | PM2.5 |
| 2023-05-18 | 223 | PM2.5 |
| 2023-05-17 | 180 | PM2.5 |
| 2023-07-15 | 173 | PM2.5 |
| 2023-07-16 | 163 | PM2.5 |
The air on a normal day
Across 3,564 monitored days from 2016 to 2025, the air in Hughes County rated Good on 94% of them, more often than the 72% typical of monitored counties, and Moderate on 6%. The median day sat at AQI 15; one day in ten went above 40.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)100%3,564 days
Every recent year on file
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 358 | 333 | 24 | 1 | 0 | 18 | 112 |
| 2024 | 363 | 340 | 23 | 0 | 0 | 8 | 69 |
| 2023 | 359 | 321 | 30 | 8 | 5 | 14 | 223 |
| 2022 | 362 | 352 | 10 | 0 | 0 | 7 | 63 |
| 2021 | 349 | 325 | 22 | 2 | 1 | 12 | 268 |
| 2020 | 355 | 332 | 23 | 0 | 0 | 19 | 79 |
| 2019 | 356 | 338 | 18 | 0 | 0 | 14 | 69 |
| 2018 | 354 | 327 | 26 | 1 | 0 | 18 | 108 |
| 2017 | 356 | 343 | 13 | 0 | 0 | 16 | 98 |
| 2016 | 352 | 341 | 11 | 0 | 0 | 22 | 69 |
| 2015 | 361 | 331 | 28 | 2 | 1 | 21 | 152 |
*2025 may be a partial year in EPA's file.
Elsewhere in South Dakota
- Clay County6/yr
- Minnehaha County5/yr
- Pennington County4/yr
- Brown County3/yr
- Brookings County3/yr
- Custer County3/yr
- Codington County3/yr
- Jackson County2/yr
How this is counted
A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day.