Tornadoes and Damaging Winds in Iowa, September 12, 1991

Name: Tornadoes and Damaging Winds in Iowa, September 12, 1991
Start: 1991-09-12T14:10
End: 1991-09-12T17:45
Location: Iowa

September 12, 1991 · NWS DSM · 21 events in 13 counties and zones

16 thunderstorm wind, 5 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: 0
Injuries: 0
Property damage: $303,000
Crop damage: None recorded
Events: 21

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

16 thunderstorm wind, 5 tornado. Local standard time, as filed.

Thunderstorm Wind, Story

When: September 12, 2:10 PM CST
Where: Story County
Measured: 50 kt (58 mph)
Coordinates: 41.900, -93.530

Thunderstorm Wind, Story

When: September 12, 2:15 PM CST
Where: Story County
Measured: 50 kt (58 mph)
Coordinates: 42.020, -93.320

Tornado, Marshall

When: September 12, 2:30 PM CST
Where: Marshall County
Rating: F1
Path length: 0.6 mi
Path width: 20 yd
Property damage: $25,000
Coordinates: 42.170, -93.000

Thunderstorm Wind, Polk

When: September 12, 2:30 PM CST
Where: Polk County
Measured: 50 kt (58 mph)
Coordinates: 41.630, -93.620

Thunderstorm Wind, Marshall

When: September 12, 2:47 PM CST
Where: Marshall County
Measured: 50 kt (58 mph)
Coordinates: 42.050, -92.920

Thunderstorm Wind, Jasper

When: September 12, 2:50 PM CST
Where: Jasper County
Measured: 50 kt (58 mph)
Coordinates: 41.670, -93.250

Thunderstorm Wind, Tama

When: September 12, 2:52 PM CST
Where: Tama County
Measured: 61 kt (70 mph)
Coordinates: 42.000, -92.580

Tornado, Tama

When: September 12, 3:20 PM CST
Where: Tama County
Rating: F0
Path length: 0.2 mi
Path width: 13 yd
Property damage: $250
Coordinates: 42.020, -92.400

Thunderstorm Wind, Benton

When: September 12, 3:30 PM CST
Where: Benton County
Measured: 54 kt (62 mph)
Coordinates: 42.170, -92.030

Thunderstorm Wind, Linn

When: September 12, 3:42 PM CST
Where: Linn County
Measured: 58 kt (67 mph)
Coordinates: 42.000, -91.650

Tornado, Johnson

When: September 12, 3:52 PM CST
Where: Johnson County
Rating: F2
Path length: 7 mi
Path width: 70 yd
Property damage: $250,000
Coordinates: 41.670, -91.830

Tornado, Linn

When: September 12, 3:59 PM CST
Where: Linn County
Rating: F0
Path length: 0.1 mi
Path width: 20 yd
Property damage: $25,000
Coordinates: 42.000, -91.650

Thunderstorm Wind, Johnson

When: September 12, 4:10 PM CST
Where: Johnson County
Measured: 52 kt (60 mph)
Coordinates: 41.800, -91.500

Thunderstorm Wind, Cedar

When: September 12, 4:10 PM CST
Where: Cedar County
Measured: 50 kt (58 mph)
Coordinates: 41.670, -91.350

Thunderstorm Wind, Linn

When: September 12, 4:15 PM CST
Where: Linn County
Measured: 52 kt (60 mph)
Coordinates: 42.200, -91.530

Tornado, Jones

When: September 12, 4:20 PM CST
Where: Jones County
Rating: F0
Path length: 0.5 mi
Path width: 20 yd
Property damage: $3,000
Coordinates: 42.230, -91.220

Thunderstorm Wind, Delaware

When: September 12, 4:40 PM CST
Where: Delaware County
Measured: 50 kt (58 mph)
Coordinates: 42.350, -91.250

Thunderstorm Wind, Jones

When: September 12, 4:50 PM CST
Where: Jones County
Measured: 50 kt (58 mph)
Coordinates: 42.230, -91.200

Thunderstorm Wind, Scott

When: September 12, 5:05 PM CST
Where: Scott County
Measured: 50 kt (58 mph)
Coordinates: 41.530, -90.580

Thunderstorm Wind, Clinton

When: September 12, 5:38 PM CST
Where: Clinton County
Measured: 60 kt (69 mph)
Coordinates: 41.820, -90.550

Thunderstorm Wind, Scott

When: September 12, 5:45 PM CST
Where: Scott County
Measured: 50 kt (58 mph)
Coordinates: 41.670, -90.350

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.
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 1991 Every state in 1991 This day in weather history The tornado archive for Iowa, 1991 Warnings in Iowa, September 1991

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: 10026437, 10026438, 10026439, 10026440, 10026441, 10026442, 10026443, 10026444, 10026445, 10026446, 10026447, 10026448, 10026449, 10026450, 10026451, 10026452, 10026453, 10026454, 10026455, 10026456, 10026457.