Tornadoes · United States · Iowa

Tornadoes in Clayton County, Iowa

18 tornadoes have crossed Clayton County since 1950, 1 of them surveyed so far this year and still preliminary, 92nd of the 99 counties in Iowa with a tornado on record, an average of one every 4.2 years. They have killed 2 people and injured 30. 1 was 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
18
Deaths
2
Injuries
30
F4 and above
1
Worst on record
F4, April 30, 1954

The deadliest in Clayton County

The strongest

Every year with a tornado

The 16 years of the 76 in the record with a tornado in Clayton County. Each year links to every tornado in Iowa that year.

YearTornadoesDeathsInjuriesStrongest
20261Unrated
20231EF1
20191EF0
201712EF1
20131EF0
20071EF1
20011F0
19941F1
19922F1
19901F2
198921F0
19881F0
19851227F3
19651F2
19541F4
19531F3

Every tornado that crossed Clayton County

18 tornadoes, newest first. The 1 at the top is this year's, from the surveying office rather than SPC's published database, and its rating is marked as preliminary.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 17, 20264:17 PM CDTUnratedClayton0.620
March 31, 20235:32 PM CDTEF1Delaware11.190
September 12, 20195:34 PM CDTEF0Clayton4.240$30,000
July 19, 20176:08 PM CDTEF1Clayton5.84002$840,000
May 29, 20135:46 PM CDTEF0Clayton to WI6.410$20,000
March 31, 20075:29 PM CDTEF1Delaware11.8200$202,000
May 10, 20016:00 PM CDTF0Clayton1.075$10,000
May 25, 19948:05 PM CDTF1Clayton6.540$500 to $5,000
June 19, 19925:27 PM CDTF1Clayton1.023$500 to $5,000
June 19, 19925:12 PM CDTF0Clayton0.223$5,000 to $50,000
June 13, 19906:20 PM CDTF2Clayton8.067$50,000 to $500,000
June 26, 198910:30 AM CDTF0Clayton0.2201$5,000 to $50,000
May 24, 19899:30 PM CDTF0Clayton0.323$50,000 to $500,000
November 15, 19889:22 PM CSTF0Clayton0.220$5,000 to $50,000
May 30, 198510:22 PM CDTF3Clayton to WI34.01,500227$5 million to $50 million
August 25, 19658:15 PM GMT-5F2Clayton4.7100$50,000 to $500,000
April 30, 19548:00 PM GMT-5F4Linn80.4200
May 10, 19537:00 PM GMT-5F3Clayton6.6400$50,000 to $500,000

Nearby

Warnings in force in Clayton CountyThe forecast for Clayton CountyThe live radar over Clayton 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.