Tornadoes · United States · Iowa

Tornadoes in Calhoun County, Iowa

43 tornadoes have crossed Calhoun County since 1950, 2 of them surveyed so far this year and still preliminary, 35th of the 99 counties in Iowa with a tornado on record, an average of one every 1.8 years. They have killed 4 people and injured 26. 4 were rated F4 or EF4 and above.

The rating scale

Tracks are drawn in the color of the rating. The United States rated tornadoes on Ted Fujita’s F scale until 31 January 2007 and on the Enhanced Fujita scale after it. Both run from 0 to 5, and both rate the damage rather than measure the wind: the speeds are what that damage is taken to imply.

  1. F0 / EF040 to 72 mph on the F scale, 65 to 85 mph on the EF scale

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F1 / EF173 to 112 mph on the F scale, 86 to 110 mph on the EF scale

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2 / EF2113 to 157 mph on the F scale, 111 to 135 mph on the EF scale

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. F3 / EF3158 to 206 mph on the F scale, 136 to 165 mph on the EF scale

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4 / EF4207 to 260 mph on the F scale, 166 to 200 mph on the EF scale

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5 / EF5261 to 318 mph on the F scale, over 200 mph on the EF scale

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unrated

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Now

Tornadoes
43
Deaths
4
Injuries
26
F4 and above
4
Worst on record
F4, June 28, 1979

The deadliest in Calhoun County

  1. F4, Pocahontas and Calhoun counties, IowaJune 28, 19793 killed, 26 injured
  2. F4, Calhoun County, IowaJune 9, 19541 killed

The strongest

  1. F4, Carroll, Sac, Calhoun and Pocahontas counties, IowaMay 27, 1995F4, 36.0 mi (58 km)
  2. F4, Pocahontas and Calhoun counties, IowaJune 28, 1979F4, 14.9 mi (24 km)
  3. F4, Calhoun and Webster counties, IowaMay 5, 1965F4, 9.9 mi (16 km)
  4. F4, Calhoun County, IowaJune 9, 1954F4, 9.9 mi (16 km)
  5. F3, Calhoun, Pocahontas and Humboldt counties, IowaJune 7, 1953F3, 30.7 mi (49 km)
  6. EF3, Calhoun County, IowaJuly 14, 2021EF3, 10.8 mi (17 km)
  7. F2, Buena Vista and Calhoun counties, IowaAugust 5, 1958F2, 27.1 mi (44 km)
  8. F2, Sac, Calhoun and Pocahontas counties, IowaApril 26, 1984F2, 22.0 mi (35 km)
  9. EF2, Calhoun and Webster counties, IowaDecember 15, 2021EF2, 18.0 mi (29 km)
  10. F2, Pocahontas and Calhoun counties, IowaJune 19, 1990F2, 16.0 mi (26 km)

Every year with a tornado

The 29 years of the 76 in the record with a tornado in Calhoun County. Each year links to every tornado in Iowa that year.

YearTornadoesDeathsInjuriesStrongest
20262EF1
20242EF1
20232EF0
20215EF3
20152EF1
20141EF0
20082EF1
20072EF0
20061F0
20051F1
20042F0
19991F0
19983F0
19951F4
19931F0
19901F2
19891F1
19871F0
19861F2
19841F2
19811F1
19791326F4
19781F0
19771F1
19652F4
19631F0
19581F2
195411F4
19531F3

Every tornado that crossed Calhoun County

43 tornadoes, newest first. The 2 at the top are this year's, from the surveying office rather than SPC's published database, and their ratings are marked as preliminary.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 17, 20269:01 PM CDTEF1Calhoun4.250
May 17, 20269:10 PM CDTEF1Calhoun0.230
April 16, 20242:57 PM CDTUnratedCalhoun0.630
April 16, 20242:26 PM CDTEF1Calhoun5.275$12,000
May 13, 20236:22 PM CDTEF0Calhoun1.450$20,000
May 13, 20234:51 PM CDTUnratedCalhoun0.630
December 15, 20215:40 PM CSTEF2Calhoun18.080$100,000
December 15, 20215:35 PM CSTEF1Calhoun19.0100$20,000
December 15, 20215:34 PM CSTUnratedCalhoun1.340
July 14, 20213:52 PM CDTEF3Calhoun10.8505$2.5 million
May 15, 20214:35 PM CDTUnratedCalhoun0.330
May 10, 20158:14 PM CDTEF0Calhoun1.0400
May 10, 20157:10 PM CDTEF1Carroll23.3700$1.0 million
August 31, 20148:13 PM CDTEF0Calhoun1.4100$4,000
May 29, 20089:25 PM CDTEF0Calhoun2.450$30,000
May 29, 20089:23 PM CDTEF1Calhoun2.8100$50,000
September 30, 20076:26 PM CDTEF0Sac4.230
July 3, 20079:05 PM CDTEF0Calhoun0.130
August 10, 20064:57 AM CDTF0Calhoun0.230
May 18, 20056:58 PM CDTF1Calhoun24.5100$90,000
July 5, 20043:50 PM CDTF0Calhoun0.230
June 11, 20046:35 PM CDTF0Calhoun0.530
June 1, 19994:55 PM CDTF0Calhoun0.120
June 23, 199810:15 PM CDTF0Calhoun0.130
May 30, 199812:40 PM CDTF0Calhoun0.130
May 28, 19988:56 PM CDTF0Calhoun0.330
May 27, 19957:22 PM CDTF4Carroll36.0400$500,000 to $5 million
June 29, 19938:15 PM CDTF0Calhoun0.230$500 to $5,000
June 19, 19906:15 AM CDTF2Pocahontas16.077$500,000 to $5 million
April 27, 19898:35 PM CDTF1Sac15.060$500 to $5,000
August 17, 19874:54 PM CDTF0Calhoun0.413
July 28, 19868:47 PM CDTF2Calhoun4.0150$50,000 to $500,000
April 26, 19844:40 PM CSTF2Sac22.0200$500,000 to $5 million
June 23, 198111:40 PM CDTF1Calhoun1.030$5,000 to $50,000
June 28, 19797:02 PM CDTF4Pocahontas14.933326$500 to $5,000
June 25, 19785:30 PM CDTF0Calhoun0.110
May 18, 19773:28 PM CDTF1Calhoun1.020$500 to $5,000
May 15, 196512:45 PM GMT-5F2Calhoun0.550$50 to $500
May 5, 19655:15 PM GMT-5F4Calhoun9.9200$5,000 to $50,000
May 9, 19637:30 PM GMT-5F0Calhoun0.110
August 5, 19586:00 PM GMT-5F2Buena Vista27.160$500 to $5,000
June 9, 195411:00 PM GMT-5F4Calhoun9.94401$50,000 to $500,000
June 7, 195310:15 PM GMT-5F3Calhoun30.7200

Nearby

Warnings in force in Calhoun CountyThe forecast for Calhoun CountyThe live radar over Calhoun CountyEvery county in Iowa

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.