Tornadoes · United States · South Dakota
Tornadoes in Dewey County, South Dakota
28 tornadoes have crossed Dewey County since 1950, 35th of the 66 counties in South Dakota with a tornado on record, an average of one every 2.7 years. They have killed 0 people and injured 1. None was rated F4 or above.
The rating scale
Tracks are drawn in the color of the rating. The United States rated tornadoes on Ted Fujita’s F scale until 31 January 2007 and on the Enhanced Fujita scale after it. Both run from 0 to 5, and both rate the damage rather than measure the wind: the speeds are what that damage is taken to imply.
F0 / EF040 to 72 mph on the F scale, 65 to 85 mph on the EF scale
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F1 / EF173 to 112 mph on the F scale, 86 to 110 mph on the EF scale
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
F2 / EF2113 to 157 mph on the F scale, 111 to 135 mph on the EF scale
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
F3 / EF3158 to 206 mph on the F scale, 136 to 165 mph on the EF scale
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
F4 / EF4207 to 260 mph on the F scale, 166 to 200 mph on the EF scale
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
F5 / EF5261 to 318 mph on the F scale, over 200 mph on the EF scale
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.
Now
- Tornadoes
- 28
- Deaths
- 0
- Injuries
- 1
- F4 and above
- 0
- Worst on record
- EF2, June 16, 2010
The strongest
Every year with a tornado
The 19 years of the 76 in the record with a tornado in Dewey County. Each year links to every tornado in South Dakota that year.
Every tornado that crossed Dewey County
28 tornadoes, newest first.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| June 21, 2014 | 6:45 PM MDT | EF0 | Dewey | 0.3 | 20 | |||
| June 16, 2010 | 7:35 PM MDT | EF2 | Dewey | 0.4 | 50 | |||
| June 26, 2008 | 7:54 PM MDT | EF0 | Dewey | 0.2 | 50 | |||
| June 26, 2008 | 7:40 PM MDT | EF0 | Dewey | 0.3 | 50 | |||
| June 26, 2008 | 7:10 PM MDT | EF0 | Dewey | 1.2 | 100 | |||
| May 24, 2008 | 4:24 PM MDT | EF0 | Dewey | 2.6 | 400 | |||
| May 24, 2008 | 4:22 PM MDT | EF0 | Dewey | 0.1 | 20 | |||
| May 24, 2008 | 4:21 PM MDT | EF0 | Dewey | 0.1 | 20 | |||
| May 24, 2008 | 4:18 PM MDT | EF0 | Dewey | 0.1 | 20 | |||
| June 24, 2006 | 4:47 PM MDT | F0 | Dewey | 0.5 | 10 | |||
| August 2, 1997 | 3:44 PM MDT | F0 | Dewey | 0.3 | 30 | |||
| June 24, 1997 | 2:15 AM MDT | F0 | Dewey | 0.1 | 10 | |||
| May 31, 1996 | 2:41 PM MDT | F0 | Dewey | 0.3 | 10 | |||
| July 12, 1995 | 10:00 PM MDT | F0 | Dewey | 0.1 | 10 | |||
| July 6, 1994 | 2:50 PM MDT | F0 | Dewey | 0.1 | 10 | $5,000 to $50,000 | ||
| July 26, 1993 | 8:50 PM MDT | F0 | Dewey | 0.1 | 23 | |||
| June 1, 1990 | 5:55 PM MDT | F0 | Dewey | 0.3 | 20 | |||
| September 24, 1986 | 9:18 PM MDT | F1 | Dewey | 0.3 | 40 | $5,000 to $50,000 | ||
| July 23, 1985 | 7:30 PM MDT | F0 | Dewey | 0.2 | 10 | |||
| May 18, 1977 | 7:20 PM MDT | F1 | Dewey | 0.1 | 10 | $500 to $5,000 | ||
| June 19, 1970 | 5:10 PM MDT | F0 | Dewey | 0.1 | 10 | |||
| August 6, 1968 | 7:30 PM GMT-6 | F0 | Dewey | 0.1 | 10 | |||
| May 8, 1965 | 10:25 PM GMT-6 | F0 | Dewey | 0.1 | 10 | |||
| June 8, 1964 | 4:15 PM GMT-7 | F0 | Dewey | 0.1 | 10 | |||
| June 8, 1964 | 4:15 PM GMT-7 | F2 | Dewey | 3.8 | 10 | 1 | ||
| June 8, 1964 | 3:00 PM GMT-7 | F0 | Dewey | 0.1 | 10 | $5,000 to $50,000 | ||
| April 19, 1955 | 2:00 PM GMT-7 | F2 | Dewey | 0.1 | 30 | $500 to $5,000 | ||
| June 2, 1953 | 5:00 PM GMT-7 | F2 | Dewey | 5.9 | 10 | $5,000 to $50,000 |
Nearby
Warnings in force in Dewey CountyThe forecast for Dewey CountyThe live radar over Dewey CountyEvery county in South Dakota
What this means
Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.
Sources
NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.