Tornado, Bon Homme
- When
- April 20, 6:00 PM CST
- Where
- Bon Homme County
- Rating
- F2
- Path length
- 3.5 mi
- Path width
- 1,000 yd
- Property damage
- $250,000
- Coordinates
- 42.930, -97.670
Tornadoes and Hail in South Dakota, April 20, 1985
8 tornado, 4 thunderstorm wind, 1 hail, as filed by the National Weather Service.
Where it happened
Every event with a place to put it. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- $2.8 million
- Crop damage
- None recorded
- Events
- 13
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
Event by event
8 tornado, 4 thunderstorm wind, 1 hail. Local standard time, as filed.
Tornado, Bon Homme
- When
- April 20, 6:01 PM CST
- Where
- Bon Homme County
- Rating
- F1
- Path length
- 0.1 mi
- Path width
- 3 yd
- Property damage
- $25,000
- Coordinates
- 42.980, -98.070
Tornado, Yankton
- When
- April 20, 6:02 PM CST
- Where
- Yankton County
- Rating
- F0
- Path length
- 2 mi
- Path width
- 80 yd
- Coordinates
- 42.850, -97.350
Tornado, Yankton
- When
- April 20, 6:06 PM CST
- Where
- Yankton County
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 3 yd
- Coordinates
- 42.950, -97.500
Tornado, Bon Homme
- When
- April 20, 6:25 PM CST
- Where
- Bon Homme County
- Rating
- F0
- Path length
- 0.1 mi
- Path width
- 3 yd
- Coordinates
- 42.980, -97.850
Tornado, Yankton
- When
- April 20, 6:25 PM CST
- Where
- Yankton County
- Rating
- F2
- Path length
- 10 mi
- Path width
- 440 yd
- Property damage
- $25,000
- Coordinates
- 42.900, -97.600
Tornado, Clay
- When
- April 20, 6:40 PM CST
- Where
- Clay County
- Rating
- F1
- Path length
- 0.1 mi
- Path width
- 3 yd
- Property damage
- $25,000
- Coordinates
- 42.880, -96.920
Tornado, Turner
- When
- April 20, 6:45 PM CST
- Where
- Turner County
- Rating
- F2
- Path length
- 12 mi
- Path width
- 440 yd
- Property damage
- $2.5 million
- Coordinates
- 43.180, -97.230
Thunderstorm Wind, Yankton
- When
- April 20, 6:45 PM CST
- Where
- Yankton County
- Coordinates
- 43.080, -97.170
Thunderstorm Wind, Yankton
- When
- April 20, 6:45 PM CST
- Where
- Yankton County
- Coordinates
- 43.080, -97.420
Thunderstorm Wind, Lincoln
- When
- April 20, 7:25 PM CST
- Where
- Lincoln County
- Measured
- 52 kt (60 mph)
- Coordinates
- 43.450, -96.880
Thunderstorm Wind, Minnehaha
- When
- April 20, 7:45 PM CST
- Where
- Minnehaha County
- Measured
- 56 kt (64 mph)
- Coordinates
- 43.530, -96.730
Hail, Minnehaha
- When
- April 20, 7:52 PM CST
- Where
- Minnehaha County
- Measured
- 1.25 in hail
- Coordinates
- 43.580, -96.470
What these are
- Tornado
- A violently rotating column of air in contact with the ground and extending from a thunderstorm, filed with its path, width and Fujita or Enhanced Fujita rating from the damage survey.
- Thunderstorm Wind
- Winds from a thunderstorm of 50 knots (58 mph) or more, or lower winds that caused damage or casualties. Measured gusts are marked MG, estimated EG.
- Hail
- Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
More
Every storm in South Dakota in 1985Every state in 1985This day in weather historyThe tornado archive for South Dakota, 1985
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 10123681, 10123682, 10123683, 10123684, 10124536, 10124537, 10124538, 10124539, 10124540, 10124541, 10124542, 10124543, 10124544.