Tornadoes and Hail in Oklahoma, May 20, 1977

Name: Tornadoes and Hail in Oklahoma, May 20, 1977
Start: 1977-05-20T14:20
End: 1977-05-20T23:30
Location: Oklahoma

May 20, 1977 · 26 events in 16 counties and zones

15 tornado, 8 thunderstorm wind, 3 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

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The toll

Deaths: 0
Injuries: 3
Property damage: $6.9 million
Crop damage: None recorded
Events: 26

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

15 tornado, 8 thunderstorm wind, 3 hail. Local standard time, as filed.

Tornado, Jackson

When: May 20, 2:20 PM CST
Where: Jackson County
Rating: F3
Path length: 10.4 mi
Path width: 880 yd
Injuries: 3 direct, 0 indirect
Property damage: $2.5 million
Coordinates: 34.650, -99.270

Thunderstorm Wind, Jackson

When: May 20, 2:45 PM CST
Where: Jackson County
Measured: 80 kt (92 mph)
Coordinates: 34.650, -99.270

Hail, Grant

When: May 20, 3:20 PM CST
Where: Grant County
Measured: 0.75 in hail
Coordinates: 36.670, -98.050

Tornado, Major

When: May 20, 3:35 PM CST
Where: Major County
Rating: F1
Path length: 5.1 mi
Path width: 100 yd
Property damage: $25,000
Coordinates: 36.200, -98.800

Tornado, Grady

When: May 20, 3:43 PM CST
Where: Grady County
Rating: F1
Path length: 2.5 mi
Path width: 90 yd
Property damage: $25,000
Coordinates: 35.030, -97.950

Tornado, Caddo

When: May 20, 4:47 PM CST
Where: Caddo County
Rating: F2
Path length: 13.3 mi
Path width: 1,100 yd
Property damage: $250,000
Coordinates: 35.100, -98.480

Thunderstorm Wind, Roger Mills

When: May 20, 4:59 PM CST
Where: Roger Mills County
Coordinates: 35.620, -99.670

Hail, Comanche

When: May 20, 5:00 PM CST
Where: Comanche County
Measured: 1 in hail
Coordinates: 34.750, -98.130

Hail, Caddo

When: May 20, 5:05 PM CST
Where: Caddo County
Measured: 2 in hail
Coordinates: 35.230, -98.250

Tornado, Caddo

When: May 20, 5:10 PM CST
Where: Caddo County
Rating: F2
Path length: 7.8 mi
Path width: 1,760 yd
Property damage: $250,000
Coordinates: 35.280, -98.320

Tornado, Tillman

When: May 20, 5:38 PM CST
Where: Tillman County
Rating: F3
Path length: 1.5 mi
Path width: 200 yd
Property damage: $250,000
Coordinates: 34.480, -99.100

Tornado, Kiowa

When: May 20, 6:00 PM CST
Where: Kiowa County
Rating: F2
Path length: 3.6 mi
Path width: 100 yd
Property damage: $25,000
Coordinates: 34.650, -98.950

Tornado, Garfield

When: May 20, 6:15 PM CST
Where: Garfield County
Rating: F1
Path length: 4.1 mi
Path width: 100 yd
Property damage: $25,000
Coordinates: 36.300, -97.900

Thunderstorm Wind, Garfield

When: May 20, 6:36 PM CST
Where: Garfield County
Measured: 53 kt (61 mph)
Coordinates: 36.350, -97.920

Tornado, Oklahoma

When: May 20, 6:40 PM CST
Where: Oklahoma County
Rating: F2
Path length: 14.9 mi
Path width: 400 yd
Property damage: $2.5 million
Coordinates: 35.400, -97.400

Tornado, Oklahoma

When: May 20, 7:11 PM CST
Where: Oklahoma County
Rating: F3
Path length: 1.3 mi
Path width: 400 yd
Property damage: $250,000
Coordinates: 35.700, -97.300

Tornado, Logan

When: May 20, 7:15 PM CST
Where: Logan County
Rating: F3
Path length: 8.6 mi
Path width: 33 yd
Property damage: $250,000
Coordinates: 35.720, -97.300

Tornado, Logan

When: May 20, 7:20 PM CST
Where: Logan County
Rating: F2
Path length: 1.9 mi
Path width: 100 yd
Property damage: $250,000
Coordinates: 36.150, -97.630

Tornado, Logan

When: May 20, 7:30 PM CST
Where: Logan County
Rating: F1
Path length: 1.9 mi
Path width: 100 yd
Property damage: $25,000
Coordinates: 35.780, -97.550

Tornado, Grant

When: May 20, 7:45 PM CST
Where: Grant County
Path width: 33 yd
Property damage: $250,000
Coordinates: 36.800, -97.700

Thunderstorm Wind, Oklahoma

When: May 20, 8:13 PM CST
Where: Oklahoma County
Coordinates: 36.650, -97.570

Thunderstorm Wind, Canadian

When: May 20, 8:23 PM CST
Where: Canadian County
Measured: 61 kt (70 mph)
Coordinates: 35.520, -97.980

Thunderstorm Wind, Canadian

When: May 20, 11:10 PM CST
Where: Canadian County
Measured: 59 kt (68 mph)
Coordinates: 35.520, -97.980

Thunderstorm Wind, Stephens

When: May 20, 11:16 PM CST
Where: Stephens County
Measured: 56 kt (64 mph)
Coordinates: 34.600, -97.380

Thunderstorm Wind, McClain

When: May 20, 11:20 PM CST
Where: McClain County
Measured: 61 kt (70 mph)
Coordinates: 35.150, -97.480

Tornado, Garvin

When: May 20, 11:30 PM CST
Where: Garvin County
Rating: F1
Path length: 2.7 mi
Path width: 50 yd
Property damage: $25,000
Coordinates: 34.600, -97.300

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

Every storm in Oklahoma in 1977 Every state in 1977 This day in weather history The tornado archive for Oklahoma, 1977

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: 10093689, 10093690, 10093691, 10093692, 10093693, 10093694, 10093695, 10093696, 10093697, 10093698, 10093699, 10093700, 10093701, 10093702, 10093703, 10093704, 10093705, 10095810, 10095811, 10095812, 10095813, 10095814, 10095815, 10095816, 10096031, 10096032.