Tornadoes and Hail in Iowa, May 20, 1987

Name: Tornadoes and Hail in Iowa, May 20, 1987
Start: 1987-05-20T13:30
End: 1987-05-20T22:45
Location: Iowa

May 20, 1987 · NWS DSM · 13 events in 10 counties and zones

6 thunderstorm wind, 4 tornado, 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

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $1.0 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

6 thunderstorm wind, 4 tornado, 3 hail. Local standard time, as filed.

Tornado, Washington

When: May 20, 1:30 PM CST
Where: Washington County
Rating: F1
Path length: 1.5 mi
Path width: 27 yd
Property damage: $250,000
Coordinates: 41.180, -91.500

Tornado, Louisa

When: May 20, 1:33 PM CST
Where: Louisa County
Rating: F1
Path length: 11.5 mi
Path width: 27 yd
Property damage: $250,000
Coordinates: 41.220, -91.470

Tornado, Muscatine

When: May 20, 1:56 PM CST
Where: Muscatine County
Rating: F1
Path length: 12 mi
Path width: 27 yd
Property damage: $250,000
Coordinates: 41.380, -91.330

Hail, Union

When: May 20, 2:15 PM CST
Where: Union County
Measured: 1.75 in hail
Coordinates: 41.070, -94.370

Thunderstorm Wind, Muscatine

When: May 20, 4:00 PM CST
Where: Muscatine County
Measured: 54 kt (62 mph)
Coordinates: 41.420, -91.050

Thunderstorm Wind, Scott

When: May 20, 4:00 PM CST
Where: Scott County
Measured: 52 kt (60 mph)
Coordinates: 41.530, -90.580

Thunderstorm Wind, Benton

When: May 20, 4:05 PM CST
Where: Benton County
Measured: 52 kt (60 mph)
Coordinates: 42.030, -92.080

Thunderstorm Wind, Scott

When: May 20, 4:50 PM CST
Where: Scott County
Measured: 52 kt (60 mph)
Coordinates: 41.700, -90.680

Thunderstorm Wind, Mahaska

When: May 20, 5:08 PM CST
Where: Mahaska County
Measured: 52 kt (60 mph)
Coordinates: 41.300, -92.650

Hail, Bremer

When: May 20, 5:11 PM CST
Where: Bremer County
Measured: 2.75 in hail
Coordinates: 42.670, -92.350

Thunderstorm Wind, Worth

When: May 20, 6:00 PM CST
Where: Worth County
Measured: 57 kt (66 mph)
Coordinates: 43.280, -93.070

Hail, Bremer

When: May 20, 6:40 PM CST
Where: Bremer County
Measured: 0.75 in hail
Coordinates: 42.850, -92.100

Tornado, Montgomery

When: May 20, 10:45 PM CST
Where: Montgomery County
Rating: F1
Path length: 4 mi
Path width: 20 yd
Property damage: $250,000
Coordinates: 41.050, -95.000

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.
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.

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

The same day elsewhere

Every storm in Iowa in 1987 Every state in 1987 This day in weather history The tornado archive for Iowa, 1987 Warnings in Iowa, May 1987

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: 10014345, 10014346, 10014347, 10014348, 10014349, 10014350, 10014351, 10014352, 10014353, 10014354, 10014355, 10014356, 10014357.