Tornadoes · United States · Illinois

Tornadoes in Boone County, Illinois

25 tornadoes have crossed Boone County since 1950, 65th of the 102 counties in Illinois with a tornado on record, an average of one every 3.0 years. They have killed 28 people and injured 512. 2 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
25
Deaths
28
Injuries
512
F4 and above
2
Worst on record
F4, April 21, 1967

The deadliest in Boone County

  1. F4 Belvidere tornado, IllinoisApril 21, 196724 killed, 450 injured
  2. EF4 Rochelle–Fairdale tornado, IllinoisApril 9, 20152 killed, 11 injured
  3. EF1, Ogle, Winnebago and Boone counties, IllinoisMarch 31, 20231 killed, 40 injured
  4. F2, Stephenson, Winnebago, Boone and McHenry counties, IllinoisOctober 8, 19581 killed

The strongest

  1. EF4 Rochelle–Fairdale tornado, IllinoisApril 9, 2015EF4, 30.1 mi (48 km)
  2. F4 Belvidere tornado, IllinoisApril 21, 1967F4, 25.5 mi (41 km)
  3. EF3, Boone and McHenry counties, IllinoisJanuary 7, 2008EF3, 13.1 mi (21 km)
  4. F2, Stephenson, Winnebago, Boone and McHenry counties, IllinoisOctober 8, 1958F2, 81.0 mi (130 km)
  5. EF2, Boone, Winnebago and McHenry counties, IllinoisNovember 22, 2010EF2, 18.1 mi (29 km)

Every year with a tornado

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

YearTornadoesDeathsInjuriesStrongest
20251EF0
20241EF0
20233140EF1
20222EF0
20201EF1
20172EF1
20155211EF4
201016EF2
20091EF0
200825EF3
19911F0
19861F0
19841F1
1967124450F4
19591F1
195811F2

Every tornado that crossed Boone County

25 tornadoes, newest first.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 3, 20259:05 PM CDTEF0Boone0.375
May 7, 20242:05 PM CDTEF0Boone to WI14.350$60,000
July 12, 20235:25 PM CDTEF0Boone2.5175
March 31, 20237:44 PM CDTEF1Boone to WI17.3300$100,000
March 31, 20237:24 PM CDTEF1Ogle27.5600140
April 30, 20226:07 PM CDTUnratedBoone0.130
April 30, 20225:54 PM CDTEF0Boone0.560
August 10, 20202:47 PM CDTEF1Winnebago9.2300
June 28, 20178:14 PM CDTEF1Boone5.9200
May 17, 201710:21 PM CDTEF1Boone10.3100$100,000
April 9, 20157:25 PM CDTEF1Boone3.950$150,000
April 9, 20157:24 PM CDTEF0Boone0.430$20,000
April 9, 20157:15 PM CDTEF1Boone4.0100$80,000
April 9, 20156:39 PM CDTEF4Rochelle–Fairdale tornado30.1700211$19 million
April 9, 20156:37 PM CDTEF0Boone2.825
November 22, 20103:00 PM CSTEF2Boone18.12006$5.0 million
July 30, 20094:26 PM CDTEF0Boone0.320
June 12, 200812:30 AM CDTEF1Boone6.2150$25,000
January 7, 20083:30 PM CSTEF3Boone13.11005$4.0 million
April 29, 19917:30 PM CDTF0Boone3.0100$5,000 to $50,000
May 15, 19863:30 PM CDTF0Boone0.210$500 to $5,000
June 22, 19841:30 PM CDTF1Boone0.6200$5,000 to $50,000
April 21, 19673:50 PM GMT-6F4Belvidere tornado25.51,20024450$50,000 to $500,000
September 26, 19596:00 PM GMT-5F1Boone3.010$5,000 to $50,000
October 8, 195812:30 AM GMT-5F2Stephenson81.0101$500,000 to $5 million

Nearby

Warnings in force in Boone CountyThe forecast for Boone CountyThe live radar over Boone CountyEvery county in Illinois

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.