South Dakota heat wave risk
Minnehaha County has the highest heat wave risk in South Dakota, scoring 87.2 out of 100 — rated "Relatively Moderate" by FEMA's National Risk Index. Recorded heat wave events across South Dakota have increased 153% over the past five years compared to the prior five-year period.
| # | County | NRI score | Rating |
NOAA events 2016–2026 |
|---|---|---|---|---|
| 1 | Minnehaha County | 87.2 | Relatively Moderate | 19 |
| 2 | Yankton County | 63.4 | Relatively Low | 22 |
| 3 | Pennington County | 59.6 | Relatively Low | 0 |
| 4 | Brown County | 48.7 | Relatively Low | 9 |
| 5 | Beadle County | 45.2 | Relatively Low | 17 |
| 6 | Lincoln County | 42.8 | Relatively Low | 20 |
| 7 | Brookings County | 40.4 | Relatively Low | 14 |
| 8 | Lake County | 38.6 | Very Low | 18 |
| 9 | Codington County | 38.5 | Very Low | 4 |
| 10 | Roberts County | 37.2 | Very Low | 4 |
| 11 | Moody County | 34.6 | Very Low | 13 |
| 12 | Todd County | 33.9 | Very Low | 0 |
| 13 | Union County | 33.8 | Very Low | 21 |
| 14 | Oglala Lakota County | 33.1 | Very Low | 0 |
| 15 | Hughes County | 31 | Very Low | 11 |
| 16 | Grant County | 30.9 | Very Low | 7 |
| 17 | Deuel County | 30.7 | Very Low | 6 |
| 18 | Clay County | 30.1 | Very Low | 21 |
| 19 | Charles Mix County | 26.8 | Very Low | 22 |
| 20 | Hamlin County | 26.7 | Very Low | 8 |
| 21 | Davison County | 25.5 | Very Low | 21 |
| 22 | Tripp County | 24.6 | Very Low | 0 |
| 23 | Hutchinson County | 24.5 | Very Low | 21 |
| 24 | Meade County | 24.1 | Very Low | 0 |
| 25 | Dewey County | 23.3 | Very Low | 5 |
| 26 | Bon Homme County | 23.2 | Very Low | 21 |
| 27 | Day County | 23.2 | Very Low | 5 |
| 28 | Lyman County | 22.7 | Very Low | 11 |
| 29 | Kingsbury County | 21.9 | Very Low | 16 |
| 30 | Spink County | 21.9 | Very Low | 11 |
| 31 | Jackson County | 20.2 | Very Low | 0 |
| 32 | McCook County | 19.6 | Very Low | 19 |
| 33 | Turner County | 19.3 | Very Low | 20 |
| 34 | Walworth County | 18.4 | Very Low | 5 |
| 35 | Corson County | 17.8 | Very Low | 5 |
| 36 | Lawrence County | 16.9 | Very Low | 0 |
| 37 | Marshall County | 16.4 | Very Low | 5 |
| 38 | Clark County | 16.3 | Very Low | 7 |
| 39 | Hanson County | 16.1 | Very Low | 19 |
| 40 | Bennett County | 15.6 | Very Low | 0 |
| 41 | Faulk County | 15.6 | Very Low | 11 |
| 42 | Ziebach County | 15.4 | Very Low | 0 |
| 43 | Buffalo County | 15.3 | Very Low | 9 |
| 44 | Mellette County | 15.1 | Very Low | 0 |
| 45 | Brule County | 14.7 | Very Low | 16 |
| 46 | Hand County | 14.6 | Very Low | 9 |
| 47 | Butte County | 13.6 | Very Low | 0 |
| 48 | Fall River County | 13.4 | Very Low | 0 |
| 49 | Sanborn County | 12.9 | Very Low | 18 |
| 50 | McPherson County | 12.6 | Very Low | 5 |
| 51 | Edmunds County | 12.3 | Very Low | 7 |
| 52 | Stanley County | 12.3 | Very Low | 7 |
| 53 | Haakon County | 11.9 | Very Low | 0 |
| 54 | Miner County | 11.9 | Very Low | 15 |
| 55 | Douglas County | 11.8 | Very Low | 18 |
| 56 | Potter County | 10.9 | Very Low | 6 |
| 57 | Hyde County | 10.8 | Very Low | 10 |
| 58 | Gregory County | 9.3 | Very Low | 21 |
| 59 | Aurora County | 8.7 | Very Low | 19 |
| 60 | Jerauld County | 7.6 | Very Low | 15 |
| 61 | Sully County | 7.5 | Very Low | 6 |
| 62 | Perkins County | 6.5 | Very Low | 0 |
| 63 | Jones County | 6.3 | Very Low | 6 |
| 64 | Campbell County | 6.2 | Very Low | 4 |
| 65 | Custer County | 5.1 | Very Low | 0 |
| 66 | Harding County | 3.5 | Very Low | 0 |
Source: FEMA National Risk Index v1.20.0, December 2025. Scores are 0–100 percentile rankings among all US counties. See the methodology page for definitions. Download the full CSV for all counties.
Heat Wave risk nationally:
Other hazard risks in South Dakota:
Frequently asked questions
What is the highest heat wave risk county in South Dakota?
Minnehaha County, SD has the highest heat wave risk in South Dakota, with a FEMA National Risk Index score of 87.2 out of 100 (rated "Relatively Moderate").
What causes heat wave risk in South Dakota?
Heat is consistently the leading cause of weather-related mortality in the US, yet it remains underrepresented in federal disaster declarations relative to its actual impact. High scores reflect a combination of extreme temperature exposure, population vulnerability (elderly, outdoor workers), and limited access to cooling infrastructure.