Tornadoes · United States · Iowa

Tornadoes in Osceola County, Iowa

31 tornadoes have crossed Osceola County since 1950, 62nd of the 99 counties in Iowa with a tornado on record, an average of one every 2.5 years. They have killed 0 people and injured 19. 1 was rated F4 or EF4 and above. Before 1950, Grazulis's record of significant tornadoes has 4 more crossing the county, back to 1895.

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
31
Deaths
0
Injuries
19
F4 and above
1
Worst on record
EF4, June 25, 2010

The strongest

Every year with a tornado

The 19 years of the 76 in the record with a tornado in Osceola County. Each year links to every tornado in Iowa that year.

YearTornadoesDeathsInjuriesStrongest
20213EF0
20172EF2
20111EF0
2010413EF4
20082EF0
20012F0
20001F0
19981F1
199421F3
199325F2
19911F0
19821F2
19812F2
19791F0
19712F3
19681F2
19661F2
19651F2
19641F2

Every tornado that crossed Osceola County

31 tornadoes, newest first.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 20, 20213:34 PM CDTEF0Osceola3.630$30,000
August 8, 20214:47 PM CDTEF0Osceola2.450$10,000
August 8, 20214:36 PM CDTUnratedOsceola0.840
August 18, 20178:07 PM CDTEF2Osceola5.1250$300,000
August 18, 20177:47 PM CDTEF1Osceola1.6100
May 11, 20117:07 PM CDTEF0Osceola0.550
June 26, 20108:15 PM CDTEF0Osceola0.150
June 26, 20108:12 PM CDTEF0Osceola0.150
June 25, 201010:45 PM CDTEF0Osceola0.250
June 25, 20109:53 PM CDTEF4Sibley–Little Rock tornado13.780013$3.5 million
June 11, 20085:29 PM CDTEF0Osceola0.850
May 1, 20088:05 PM CDTEF0Osceola0.150
June 13, 20018:52 PM CDTF0Osceola0.150
June 12, 20019:45 PM CDTF0Osceola0.150
July 11, 20008:36 PM CDTF0Osceola0.150
June 27, 19984:45 PM CDTF1Osceola4.0100$500,000
August 7, 19949:16 PM CDTF3Osceola4.5731$50,000 to $500,000
June 12, 19946:58 PM CDTF0Osceola0.123$500 to $5,000
June 29, 19933:31 PM CDTF0Osceola0.223$50 to $500
June 7, 19936:41 PM CDTF2Osceola10.01275$5,000 to $50,000
June 2, 19915:25 PM CDTF0Osceola0.113$50 to $500
June 6, 19824:00 PM CDTF2Osceola2.067$500,000 to $5 million
June 14, 19815:00 AM CDTF2Osceola21.61,533$500,000 to $5 million
June 14, 19815:00 AM CDTF2Osceola21.91,533$500,000 to $5 million
August 19, 19795:30 PM CDTF0Osceola0.230$500 to $5,000
May 31, 19712:20 PM CDTF3Osceola8.6250$50,000 to $500,000
May 31, 19712:15 PM CDTF3O'Brien to MN46.5100$50,000 to $500,000
June 13, 19686:50 PM GMT-5F2Osceola0.1200$50,000 to $500,000
July 9, 19664:30 AM GMT-5F2Osceola1.0200$5,000 to $50,000
May 5, 19653:30 PM GMT-5F2O'Brien21.810$500 to $5,000
May 8, 19641:35 PM GMT-5F2Osceola5.1200$5,000 to $50,000

Osceola County before 1950

Before 1950 the record is Thomas P. Grazulis’s list of significant tornadoes: those rated F2 or stronger, and weaker ones that killed somebody. 4 of them crossed Osceola County, killing 4. They are not in the figures above, which are SPC's from 1950.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 30, 19425:45 PM CSTF3W Lake Park, IA to Jackson County, MN19.9600
May 17, 19315:30 PM CSTF2Ruth Lake, IA/E Lakefield, MN29.21
June 5, 19146:00 PM CSTF3NE Archer/SE Sheldon/Sanborn/S Melvin, IA11.1200320
May 3, 18954:00 PM CSTF3W Ashton to S Sibley, IA6.520011

About the record before 1950

Significant tornadoes only
Grazulis listed tornadoes rated F2 or stronger, and weaker ones that killed somebody. Most tornadoes are weaker than F2, so the list holds a fraction of the tornadoes that happened.
The early years are thin
A tornado is on record only where somebody saw it and wrote it down. The count rises through the 1800s with settlement and newspapers, not with the weather.
Rated from accounts
Grazulis rated each tornado decades later from newspaper reports, Weather Bureau records and local histories, not from a damage survey.
The tracks are reconstructed
Tornado Archive drew each path through the places Grazulis names, most often as a straight line from the first to the last. A track can miss a town it hit, and a tornado with one named place is a point. The counties are today’s.
A separate record
SPC’s database, from 1950, counts every confirmed tornado of any strength. The two are kept apart on every page and never added together.

Nearby

Warnings in force in Osceola CountyThe forecast for Osceola CountyThe live radar over Osceola 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. Before 1950: Thomas P. Grazulis, Significant Tornadoes 1680-1991 and Significant Tornadoes 1880-1989, as digitized by Tornado Archive (Maas and others, 2024). Public domain. Counties assigned by this site from today’s NWS county lines.