Dewey County, South Dakota: hazard risk
FEMA rates Dewey County's overall risk Relatively Low (score 78.7 of 100, higher than 78% of rated U.S. counties); 2 of its 13 hazards are rated Relatively High or Very High, led by cold wave, winter weather. Its storm record holds 814 events since 1950.
FEMA's rating for each hazard
These are FEMA's county-wide model ratings and this county's storm record. They are not an assessment of any property, address or building, and not insurance advice: a property's risk depends on its own elevation, construction and location.
FEMA gives each hazard its own rating, and a rating does not follow the score from one hazard to the next: a hazard with a higher score can carry a lower rating than another. The table sorts by FEMA's rating, then by score (0 to 100, the county against every other county for that hazard).
| Hazard | Risk rating | Score | Expected annual loss |
|---|---|---|---|
| Cold Wave | Very High | 99.0 | $20M |
| Winter Weather | Relatively High | 85.3 | $159K |
| Ice Storm | Relatively Moderate | 65.2 | $94K |
| Wildfire | Relatively Low | 83.0 | $318K |
| Hail | Relatively Low | 57.8 | $195K |
| Strong Wind | Relatively Low | 23.0 | $119K |
| Landslide | Very Low | 31.9 | $201 |
| Drought | Very Low | 28.1 | $11K |
| Tornado | Very Low | 24.4 | $192K |
| Heat Wave | Very Low | 23.3 | $47K |
| Riverine Flooding | Very Low | 17.4 | $1.2M |
| Lightning | Very Low | 16.4 | $31K |
| Earthquake | Very Low | 12.2 | $7K |
Source: FEMA National Risk Index, December 2025 release. A model of future loss, not a count of past events. FEMA's National Risk Index map.
What the record holds
| Hazard | Records | Deaths | Damage | Rank in state | Rank in U.S. |
|---|---|---|---|---|---|
| Hail | 265 | 0 | – | 64th of 66 | 2274th of 3,080 |
| Severe thunderstorm wind | 194 | 0 | $10K | 66th of 66 | 2567th of 3,080 |
| Winter storms | 94 | 0 | $274K | 65th of 66 | 2384th of 3,077 |
| High wind and dust storms | 84 | 0 | – | 62nd of 66 | 1199th of 3,080 |
| Drought | 64 | 0 | – | 41st of 66 | 1402nd of 3,063 |
| Extreme cold | 37 | 3 | – | 47th of 66 | 1336th of 3,076 |
| Floods | 34 | 0 | $4.7M | 59th of 66 | 2637th of 3,080 |
| Tornadoes | 27 | 0 | $720K | 55th of 66 | 2473rd of 3,080 |
| Heat | 8 | 0 | $8K | 49th of 66 | 2043rd of 3,076 |
| Wildfires | 3 | 0 | – | 24th of 66 | 1057th of 2,972 |
| Lightning | 1 | 0 | – | 41st of 66 | 2366th of 3,080 |
Source: NOAA NCEI Storm Events Database, 1950 to 2026-06-30; damage in 2025 dollars. Search the record at NCEI.
The full Dewey County record: every hazard by year and month, the deadliest events and FEMA's declarations.