Tornado and Hail in Iowa, July 20, 1994

Name: Tornado and Hail in Iowa, July 20, 1994
Start: 1994-07-20T00:15
End: 1994-07-20T17:12
Location: Iowa

July 20, 1994 · 8 events in 5 counties and zones

6 thunderstorm wind, 1 hail, 1 tornado, as filed by the National Weather Service.

Where it happened

Every event with a place to put it; 8 filed by county or forecast zone are drawn at its center, in a lighter ring. 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: 0
Property damage: $530,000
Crop damage: $53,000
Events: 8

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, 1 hail, 1 tornado. Local standard time, as filed.

Thunderstorm Wind, Dubuque

When: July 20, 12:15 AM CST
Where: Dubuque County, Dubuque
Measured: 50 kt (58 mph)
Property damage: $5,000
Crop damage: $500
Coordinates: 42.469, -90.882 (the zone’s center; the record gives no point)

Thunderstorm Wind, Jones

When: July 20, 12:15 AM CST
Where: Jones County, Monticello
Measured: 50 kt (58 mph)
Property damage: $5,000
Crop damage: $500
Coordinates: 42.121, -91.131 (the zone’s center; the record gives no point)

Thunderstorm Wind, Linn

When: July 20, 12:20 AM CST
Where: Linn County, Cedar Rapids Arpt
Measured: 54 kt (62 mph)
Property damage: $5,000
Crop damage: $500
Coordinates: 42.079, -91.599 (the zone’s center; the record gives no point)

Thunderstorm Wind, Dubuque

When: July 20, 12:21 AM CST
Where: Dubuque County, Dubuque
Measured: 50 kt (58 mph)
Property damage: $500,000
Crop damage: $500
Coordinates: 42.469, -90.882 (the zone’s center; the record gives no point)

Thunderstorm Wind, Dubuque

When: July 20, 12:29 AM CST
Where: Dubuque County, Dubuque
Measured: 50 kt (58 mph)
Property damage: $5,000
Crop damage: $500
Coordinates: 42.469, -90.882 (the zone’s center; the record gives no point)

Thunderstorm Wind, Jones

When: July 20, 12:43 AM CST
Where: Jones County, Monticello
Measured: 50 kt (58 mph)
Property damage: $5,000
Crop damage: $500
Coordinates: 42.121, -91.131 (the zone’s center; the record gives no point)

Hail, Cedar

When: July 20, 12:50 AM CST
Where: Cedar County, Mechanicsville
Measured: 0.75 in hail
Property damage: $5,000
Crop damage: $50,000
Coordinates: 41.772, -91.132 (the zone’s center; the record gives no point)

Tornado, Woodbury

When: July 20, 5:12 PM CST
Where: Woodbury County, Salix
Path length: 0.1 mi
Path width: 20 yd
Property damage: $50
Crop damage: $50
Coordinates: 42.390, -96.045 (the zone’s center; the record gives no point)

Following the passage of the cold front the previous night, Iowa was under a cyclonic flow regime. Unseasonably cold air aloft made conditions conducive for convective development during the later part of the afternoon. One thunderstorm moved into southwest Woodbury County. A tornado touched down briefly near Salix in an open area. It is believed that this tornado was the product of a brief touch down of a cold air funnel.

What these are

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.
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 1994 Every state in 1994 This day in weather history The tornado archive for Iowa, 1994 Warnings in Iowa, July 1994

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: 10321749, 10324330, 10324430, 10321750, 10321751, 10324331, 10321443, 10324123.