Tornadoes · United States · North Dakota · 1957
F5 Fargo tornado, North Dakota, June 20, 1957
This F5 tornado ran 52.4 miles across Cass and Clay counties on June 20, 1957, touching down at 7:40 PM GMT-5 and reaching 500 yards wide. It killed 10 people and injured 103, and did $5 million to $50 million of property damage.
The rating scale
Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
F040 to 72 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
F2113 to 157 mph
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.
F3158 to 206 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
F4207 to 260 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
F5261 to 318 mphthis tornado
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.
The record
- Rating
- F5
- Date
- June 20, 1957
- Touchdown
- 7:40 PM GMT-5 (00:40 UTC)
- Path length
- 52.4 miles (84.3 km)
- Path width
- 500 yards (457 m)
- Deaths
- 10
- Injuries
- 103
- Property damage
- $5 million to $50 million
- Counties
- Cass and Clay counties
- Touchdown point
- 46.900, -97.350
- Lift-off point
- 46.870, -96.230
- Record number
- 591
The surface observations
Fargo (FAR), 5 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 23:00 UTC | 83 | 68 | 160° 15 kt | 998.3 | ||
| 00:00 UTC | 80 | 69 | 140° 13 kt | 997 | -TSRA |
From the Iowa Environmental Mesonet's archive of airport observations.
This ground now
The live radar over the trackEvery 1957 tornado in North DakotaEvery tornado in North Dakota since 1950Warnings in force in North Dakota nowThe forecast where you are
The other tornadoes of June 20, 1957
4 more were confirmed in the United States that day.
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.