Tornado and Hail in Iowa, June 20, 1974

Name: Tornado and Hail in Iowa, June 20, 1974
Start: 1974-06-20T14:30
End: 1974-06-20T22:15
Location: Iowa

June 20, 1974 · 71 events in 38 counties and zones

54 thunderstorm wind, 16 hail, 1 tornado, 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

Open the live radar over this ground

The toll

Deaths: 1
Injuries: 20
Property damage: $2.5 million
Crop damage: None recorded
Events: 71

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

54 thunderstorm wind, 16 hail, 1 tornado. Local standard time, as filed.

Hail, Worth

When: June 20, 2:30 PM CST
Where: Worth County
Measured: 0.75 in hail
Coordinates: 43.450, -93.220

Thunderstorm Wind, Worth

When: June 20, 2:30 PM CST
Where: Worth County
Coordinates: 43.450, -93.220

Hail, Howard

When: June 20, 2:40 PM CST
Where: Howard County
Measured: 0.75 in hail
Coordinates: 43.370, -92.300

Thunderstorm Wind, Howard

When: June 20, 2:40 PM CST
Where: Howard County
Coordinates: 43.370, -92.300

Thunderstorm Wind, Mitchell

When: June 20, 2:40 PM CST
Where: Mitchell County
Coordinates: 43.280, -92.820

Thunderstorm Wind, Winneshiek

When: June 20, 2:50 PM CST
Where: Winneshiek County
Coordinates: 43.300, -91.800

Hail, Allamakee

When: June 20, 3:00 PM CST
Where: Allamakee County
Measured: 1.75 in hail
Coordinates: 43.380, -91.230

Thunderstorm Wind, Allamakee

When: June 20, 3:00 PM CST
Where: Allamakee County
Coordinates: 43.380, -91.230

Thunderstorm Wind, Chickasaw

When: June 20, 3:00 PM CST
Where: Chickasaw County
Coordinates: 43.070, -92.330

Thunderstorm Wind, Allamakee

When: June 20, 3:00 PM CST
Where: Allamakee County
Coordinates: 43.270, -91.480

Thunderstorm Wind, Winneshiek

When: June 20, 3:00 PM CST
Where: Winneshiek County
Coordinates: 43.120, -92.030

Thunderstorm Wind, Floyd

When: June 20, 3:05 PM CST
Where: Floyd County
Coordinates: 43.070, -92.700

Hail, Kossuth

When: June 20, 3:15 PM CST
Where: Kossuth County
Measured: 1.75 in hail
Coordinates: 43.380, -94.100

Thunderstorm Wind, Fayette

When: June 20, 3:15 PM CST
Where: Fayette County
Coordinates: 42.970, -91.800

Thunderstorm Wind, Allamakee

When: June 20, 3:15 PM CST
Where: Allamakee County
Coordinates: 43.070, -91.470

Thunderstorm Wind, Clayton

When: June 20, 3:30 PM CST
Where: Clayton County
Coordinates: 42.850, -91.400

Thunderstorm Wind, Butler

When: June 20, 3:30 PM CST
Where: Butler County
Coordinates: 42.750, -92.780

Thunderstorm Wind, Bremer

When: June 20, 3:30 PM CST
Where: Bremer County
Coordinates: 42.730, -92.480

Thunderstorm Wind, Fayette

When: June 20, 3:35 PM CST
Where: Fayette County
Coordinates: 42.680, -91.900

Thunderstorm Wind, Black Hawk

When: June 20, 3:40 PM CST
Where: Black Hawk County
Measured: 56 kt (64 mph)
Coordinates: 42.550, -92.400

Hail, Winnebago

When: June 20, 3:45 PM CST
Where: Winnebago County
Measured: 1.75 in hail
Coordinates: 43.270, -93.650

Hail, Hancock

When: June 20, 3:45 PM CST
Where: Hancock County
Measured: 1.75 in hail
Coordinates: 43.020, -93.600

Thunderstorm Wind, Winnebago

When: June 20, 3:45 PM CST
Where: Winnebago County
Coordinates: 43.270, -93.650

Thunderstorm Wind, Hancock

When: June 20, 3:45 PM CST
Where: Hancock County
Coordinates: 43.020, -93.600

Thunderstorm Wind, Buchanan

When: June 20, 3:50 PM CST
Where: Buchanan County
Coordinates: 42.470, -91.880

Thunderstorm Wind, Delaware

When: June 20, 4:00 PM CST
Where: Delaware County
Coordinates: 42.480, -91.450

Thunderstorm Wind, Delaware

When: June 20, 4:05 PM CST
Where: Delaware County
Coordinates: 42.600, -91.070

Hail, Cerro Gordo

When: June 20, 4:15 PM CST
Where: Cerro Gordo County
Measured: 0.75 in hail
Coordinates: 43.070, -93.280

Thunderstorm Wind, Grundy

When: June 20, 4:15 PM CST
Where: Grundy County
Coordinates: 42.370, -92.670

Thunderstorm Wind, Benton

When: June 20, 4:20 PM CST
Where: Benton County
Coordinates: 42.170, -92.030

Thunderstorm Wind, Linn

When: June 20, 4:20 PM CST
Where: Linn County
Coordinates: 42.030, -91.450

Thunderstorm Wind, Tama

When: June 20, 4:30 PM CST
Where: Tama County
Coordinates: 42.080, -92.400

Thunderstorm Wind, Dubuque

When: June 20, 4:30 PM CST
Where: Dubuque County
Coordinates: 42.300, -91.020

Thunderstorm Wind, Dubuque

When: June 20, 4:32 PM CST
Where: Dubuque County
Measured: 74 kt (85 mph)
Coordinates: 42.400, -90.720

Thunderstorm Wind, Jones

When: June 20, 4:35 PM CST
Where: Jones County
Coordinates: 42.120, -91.280

Hail,

When: June 20, 4:40 PM CST
Where: County
Measured: 0.75 in hail
Coordinates: 42.270, -90.370

Thunderstorm Wind,

When: June 20, 4:40 PM CST
Where: County
Coordinates: 42.270, -90.370

Thunderstorm Wind, Jones

When: June 20, 4:40 PM CST
Where: Jones County
Coordinates: 42.000, -91.130

Thunderstorm Wind, Jackson

When: June 20, 4:40 PM CST
Where: Jackson County
Coordinates: 42.130, -90.770

Thunderstorm Wind, Linn

When: June 20, 4:42 PM CST
Where: Linn County
Coordinates: 41.920, -91.380

Tornado, Clinton

When: June 20, 4:45 PM CST
Where: Clinton County
Rating: F3
Path length: 10.6 mi
Path width: 200 yd
Deaths: 1 direct, 0 indirect
Injuries: 20 direct, 0 indirect
Property damage: $2.5 million
Coordinates: 41.980, -90.270

Thunderstorm Wind, Cedar

When: June 20, 4:45 PM CST
Where: Cedar County
Coordinates: 41.900, -91.150

Thunderstorm Wind, Linn

When: June 20, 4:46 PM CST
Where: Linn County
Measured: 57 kt (66 mph)
Coordinates: 41.880, -91.720

Hail,

When: June 20, 4:50 PM CST
Where: County
Measured: 1 in hail
Coordinates: 42.070, -90.170

Thunderstorm Wind, Clinton

When: June 20, 4:50 PM CST
Where: Clinton County
Coordinates: 41.900, -90.600

Thunderstorm Wind, Cedar

When: June 20, 4:50 PM CST
Where: Cedar County
Measured: 78 kt (90 mph)
Coordinates: 41.850, -90.930

Thunderstorm Wind,

When: June 20, 4:50 PM CST
Where: County
Coordinates: 42.070, -90.170

Thunderstorm Wind, Scott

When: June 20, 4:55 PM CST
Where: Scott County
Coordinates: 41.730, -90.580

Thunderstorm Wind, Cedar

When: June 20, 4:55 PM CST
Where: Cedar County
Coordinates: 41.670, -91.170

Thunderstorm Wind, Johnson

When: June 20, 5:00 PM CST
Where: Johnson County
Coordinates: 41.670, -91.480

Thunderstorm Wind, Clinton

When: June 20, 5:00 PM CST
Where: Clinton County
Coordinates: 41.830, -90.200

Thunderstorm Wind, Scott

When: June 20, 5:08 PM CST
Where: Scott County
Coordinates: 41.530, -90.580

Thunderstorm Wind, Muscatine

When: June 20, 5:15 PM CST
Where: Muscatine County
Coordinates: 41.420, -91.050

Hail, Iowa

When: June 20, 5:30 PM CST
Where: Iowa County
Measured: 1.75 in hail
Coordinates: 41.800, -92.070

Thunderstorm Wind, Iowa

When: June 20, 5:30 PM CST
Where: Iowa County
Coordinates: 41.800, -92.070

Thunderstorm Wind, Louisa

When: June 20, 5:40 PM CST
Where: Louisa County
Coordinates: 41.180, -91.200

Hail, Johnson

When: June 20, 6:00 PM CST
Where: Johnson County
Measured: 1.75 in hail
Coordinates: 41.530, -91.780

Thunderstorm Wind, Johnson

When: June 20, 6:00 PM CST
Where: Johnson County
Coordinates: 41.530, -91.780

Hail, Washington

When: June 20, 6:40 PM CST
Where: Washington County
Measured: 1.75 in hail
Coordinates: 41.280, -91.570

Thunderstorm Wind, Washington

When: June 20, 6:40 PM CST
Where: Washington County
Coordinates: 41.280, -91.570

Thunderstorm Wind, Keokuk

When: June 20, 6:50 PM CST
Where: Keokuk County
Coordinates: 41.180, -92.000

Hail, Des Moines

When: June 20, 7:10 PM CST
Where: Des Moines County
Measured: 1.75 in hail
Coordinates: 41.020, -91.320

Thunderstorm Wind, Des Moines

When: June 20, 7:10 PM CST
Where: Des Moines County
Coordinates: 41.020, -91.320

Thunderstorm Wind, Henry

When: June 20, 7:40 PM CST
Where: Henry County
Coordinates: 40.930, -91.620

Hail, Des Moines

When: June 20, 7:45 PM CST
Where: Des Moines County
Measured: 1.75 in hail
Coordinates: 40.820, -91.080

Thunderstorm Wind, Lee

When: June 20, 7:58 PM CST
Where: Lee County
Measured: 70 kt (81 mph)
Coordinates: 40.780, -91.120

Thunderstorm Wind, Lee

When: June 20, 8:20 PM CST
Where: Lee County
Coordinates: 40.650, -91.550

Hail, Allamakee

When: June 20, 10:15 PM CST
Where: Allamakee County
Measured: 0.75 in hail
Coordinates: 43.270, -91.330

Hail, Winneshiek

When: June 20, 10:15 PM CST
Where: Winneshiek County
Measured: 0.75 in hail
Coordinates: 43.300, -91.800

Thunderstorm Wind, Allamakee

When: June 20, 10:15 PM CST
Where: Allamakee County
Coordinates: 43.270, -91.330

Thunderstorm Wind, Winneshiek

When: June 20, 10:15 PM CST
Where: Winneshiek County
Coordinates: 43.300, -91.800

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

Event	Date	Age	Sex	Where	Kind
Tornado, Clinton	1974-06-20				Direct

What these are

Hail: Hail three-quarters of an inch or larger, or smaller hail that caused damage, filed with the largest stone measured.
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.
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.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Iowa in 1974 Every state in 1974 This day in weather history The tornado archive for Iowa, 1974

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: 10012305, 10013159, 10013160, 10013161, 10013376, 10013377, 10013378, 10013379, 10013380, 10013381, 10013382, 10013383, 10013384, 10013385, 10013386, 10013387, 10013388, 10013389, 10013390, 10013391, 10013392, 10013393, 10013394, 10013395, 10013396, 10013397, 10013398, 10013399, 10013400, 10013401, 10013402, 10013403, 10013404, 10013405, 10013406, 10013407, 10013408, 10013409, 10013410, 10013411, and more.