Tornadoes · United States · Colorado

Tornadoes in Larimer County, Colorado

33 tornadoes have crossed Larimer County since 1950, 22nd of the 54 counties in Colorado with a tornado on record, an average of one every 2.3 years. They have killed 1 person and injured 78. None was rated F4 or 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
33
Deaths
1
Injuries
78
F4 and above
0
Worst on record
EF3, May 22, 2008

The deadliest in Larimer County

The strongest

Every year with a tornado

The 23 years of the 76 in the record with a tornado in Larimer County. Each year links to every tornado in Colorado that year.

YearTornadoesDeathsInjuriesStrongest
20181EF0
20151EF3
20081178EF3
20051F0
20021F0
19951F0
19943F0
19932F0
19911F0
19904F2
19891F0
19883F1
19872F1
19851F1
19831F1
19821F1
19801F1
19791F0
19761F2
19651F0
19631F1
19572F2
19541F1

Every tornado that crossed Larimer County

33 tornadoes, newest first.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 18, 20182:39 PM MDTEF0Larimer0.025
June 4, 20156:30 PM MDTEF3Boulder6.7440
May 22, 200811:26 AM MDTEF3Weld38.71,760178$147 million
July 25, 20052:36 PM MDTF0Larimer0.150
May 9, 20024:00 PM MDTF0Larimer0.150
May 6, 19959:15 AM MDTF0Larimer0.150
July 16, 19944:45 PM MDTF0Larimer0.110
July 16, 19944:24 PM MDTF0Larimer0.110
July 16, 19944:00 PM MDTF0Larimer0.110
August 5, 19933:00 PM MDTF0Larimer0.110
May 28, 19934:12 PM MDTF0Larimer0.1100
June 22, 19913:29 PM MDTF0Larimer0.110
July 8, 199011:38 AM MDTF0Larimer3.013
June 9, 19906:09 PM MDTF2Larimer23.0200$5,000 to $50,000
June 9, 19906:04 PM MDTF1Larimer1.050
June 6, 19905:30 PM MDTF0Larimer1.023$500 to $5,000
May 31, 198910:45 AM MDTF0Larimer0.113
August 7, 19883:35 PM MDTF0Larimer0.120
June 25, 19883:46 PM MDTF1Larimer1.063
June 15, 19885:38 PM MDTF1Larimer1.050$500 to $5,000
August 7, 19873:30 PM MDTF1Larimer0.520
June 18, 19875:20 PM MDTF1Larimer1.040$5,000 to $50,000
August 2, 19855:33 PM MDTF1Larimer0.320
July 7, 19838:27 PM MDTF1Larimer0.230under $50
June 25, 19827:48 PM MDTF1Larimer1.0100under $50
May 24, 19808:15 PM MDTF1Larimer1.040$500 to $5,000
July 22, 19799:15 PM MDTF0Larimer1.027
June 4, 19764:30 PM MDTF2Larimer0.5300
June 23, 19654:21 PM GMT-6F0Larimer0.110
July 7, 19636:30 PM GMT-7F1Larimer0.510$500 to $5,000
May 30, 19573:00 PM GMT-7F2Weld9.110$500 to $5,000
May 29, 19571:00 PM GMT-7F1Larimer6.110$50 to $500
August 7, 19543:00 PM GMT-7F1Larimer2.010$500 to $5,000

Nearby

Warnings in force in Larimer CountyThe forecast for Larimer CountyThe live radar over Larimer CountyEvery county in Colorado

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.