Tornado, Mahaska
- When
- May 12, 12:01 AM CST
- Where
- Mahaska County
- Rating
- F1
- Path length
- 0.3 mi
- Path width
- 3 yd
- Property damage
- $3,000
- Coordinates
- 41.170, -92.830
Tornadoes and Hail in Iowa, May 12, 1970
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
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- $278,000
- Crop damage
- None recorded
- Events
- 7
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
4 tornado, 3 hail. Local standard time, as filed.
Hail, Black Hawk
- When
- May 12, 5:45 PM CST
- Where
- Black Hawk County
- Measured
- 1.75 in hail
- Coordinates
- 42.580, -92.080
Tornado, Pottawattamie
- When
- May 12, 7:30 PM CST
- Where
- Pottawattamie County
- Rating
- F2
- Path length
- 5.9 mi
- Path width
- 400 yd
- Property damage
- $250,000
- Coordinates
- 41.470, -95.230
Hail, Story
- When
- May 12, 8:43 PM CST
- Where
- Story County
- Measured
- 0.75 in hail
- Coordinates
- 42.000, -93.580
Tornado, Story
- When
- May 12, 9:00 PM CST
- Where
- Story County
- Rating
- F1
- Path width
- 33 yd
- Property damage
- $30
- Coordinates
- 42.020, -93.450
Tornado, Story
- When
- May 12, 9:15 PM CST
- Where
- Story County
- Rating
- F1
- Path width
- 33 yd
- Property damage
- $25,000
- Coordinates
- 42.150, -93.330
Hail, Dallas
- When
- May 12, 11:14 PM CST
- Where
- Dallas County
- Measured
- 1.5 in hail
- Coordinates
- 41.580, -94.000
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.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Tornado and Hail in Nebraska, May 12, 1970
- Tornadoes and Hail in Ohio, May 12, 1970
- Tornado and Hail in Texas, May 12, 1970
- Hail in Oklahoma, May 12, 1970
- Hail and Damaging Wind in Indiana, May 12, 1970
- Hail and Damaging Winds in Illinois, May 12, 1970
- Hail in Kansas, May 12, 1970
- Hail in Wisconsin, May 12, 1970
- Hail in Missouri, May 12, 1970
- Damaging Wind in Minnesota, May 12, 1970
- Hail in South Dakota, May 12, 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: 10014643, 10014644, 10014645, 10014646, 10014647, 10014648, 10014649.