Tornado, Butler
- When
- September 9, 2:42 PM CST
- Where
- Butler County
- Rating
- F2
- Path length
- 1.9 mi
- Path width
- 200 yd
- Property damage
- $25,000
- Coordinates
- 42.900, -92.800
Tornadoes and Damaging Winds in Iowa, September 9, 1970
7 thunderstorm wind, 4 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
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- $300,000
- Crop damage
- None recorded
- Events
- 11
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
7 thunderstorm wind, 4 tornado. Local standard time, as filed.
Tornado, Bremer
- When
- September 9, 3:00 PM CST
- Where
- Bremer County
- Rating
- F2
- Path length
- 2.3 mi
- Path width
- 150 yd
- Property damage
- $25,000
- Coordinates
- 42.850, -92.530
Thunderstorm Wind, Winneshiek
- When
- September 9, 4:00 PM CST
- Where
- Winneshiek County
- Coordinates
- 43.200, -91.780
Thunderstorm Wind, Poweshiek
- When
- September 9, 4:30 PM CST
- Where
- Poweshiek County
- Coordinates
- 41.580, -92.500
Tornado, Dubuque
- When
- September 9, 4:40 PM CST
- Where
- Dubuque County
- Rating
- F2
- Path length
- 1 mi
- Path width
- 100 yd
- Property damage
- $250,000
- Coordinates
- 42.500, -91.100
Thunderstorm Wind, Wapello
- When
- September 9, 4:58 PM CST
- Where
- Wapello County
- Measured
- 58 kt (67 mph)
- Coordinates
- 41.080, -92.400
Thunderstorm Wind, Iowa
- When
- September 9, 5:00 PM CST
- Where
- Iowa County
- Coordinates
- 41.700, -92.000
Thunderstorm Wind, Linn
- When
- September 9, 5:05 PM CST
- Where
- Linn County
- Measured
- 55 kt (63 mph)
- Coordinates
- 41.880, -91.680
Tornado, Dubuque
- When
- September 9, 5:25 PM CST
- Where
- Dubuque County
- Rating
- F3
- Path length
- 4.7 mi
- Path width
- 300 yd
- Coordinates
- 42.500, -90.670
Thunderstorm Wind, Lee
- When
- September 9, 6:45 PM CST
- Where
- Lee County
- Coordinates
- 40.700, -91.280
Thunderstorm Wind,
- When
- September 9, 6:51 PM CST
- Where
- County
- Coordinates
- 40.780, -91.080
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.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Tornadoes in Wisconsin, September 9, 1970
- Tornado and Damaging Winds in Illinois, September 9, 1970
- Tornado in Kentucky, September 9, 1970
- Damaging Winds in Kansas, September 9, 1970
- Damaging Winds in Missouri, September 9, 1970
- Damaging Winds in Michigan, September 9, 1970
- Damaging Wind in Oklahoma, September 9, 1970
More
Every storm in Iowa in 1970Every state in 1970This day in weather historyThe tornado archive for Iowa, 1970
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: 10011328, 10011329, 10011330, 10011331, 10011332, 10011333, 10011334, 10011335, 10011336, 10011337, 10011338.