Tornadoes · United States

Tornadoes in Montana

444 tornadoes since 1950, an average of 5.8 a year, 32nd of the 53 states and territories in the record. They have killed 4 people and injured 32. 1 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.

The deadliest in Montana

  1. EF3, Sheridan County, MontanaJuly 26, 20102 killed, 1 injured
  2. F1, McCone County, MontanaJuly 9, 19831 killed, 1 injured
  3. F3, Wibaux and Golden Valley counties, Montana and North DakotaJuly 19, 19521 killed, 2 injured

The strongest

  1. F4, Dawson County, MontanaJune 29, 1961F4, 15.9 mi (26 km)
  2. F3, Fallon County, MontanaJuly 19, 1952F3, 55.5 mi (89 km)
  3. F3, Yellowstone County, MontanaJune 16, 1965F3, 20.6 mi (33 km)
  4. EF3, Sheridan County, MontanaJuly 26, 2010EF3, 18.0 mi (29 km)
  5. F3, Wibaux and Golden Valley counties, Montana and North DakotaJuly 19, 1952F3, 16.4 mi (26 km)
  6. F3, Chouteau County, MontanaJuly 5, 1988F3, 12.0 mi (19 km)
  7. EF3, Carter County, MontanaJune 17, 2014EF3, 10.0 mi (16 km)
  8. F3, Chouteau County, MontanaJuly 5, 1988F3, 10.0 mi (16 km)
  9. F3, Wibaux County, MontanaMay 24, 1953F3, 9.3 mi (15 km)
  10. EF3, Fallon County, MontanaJune 11, 2016EF3, 3.0 mi (5 km)
  11. F3, Chouteau County, MontanaJuly 5, 1988F3, 3.0 mi (5 km)
  12. F2, Valley County, MontanaAugust 4, 1962F2, 42.9 mi (69 km)

The longest paths

  1. F3, Fallon County, MontanaJuly 19, 195255.5 mi (89 km)
  2. F2, Valley County, MontanaAugust 4, 196242.9 mi (69 km)
  3. F2, Prairie, Fallon and Custer counties, MontanaJuly 18, 196240.6 mi (65 km)
  4. F2, Dawson County, MontanaJune 23, 195333.5 mi (54 km)
  5. F0, Carter County, MontanaJune 6, 200530.0 mi (48 km)
  6. F0, Phillips and Valley counties, MontanaJuly 20, 200129.0 mi (47 km)
  7. F0, McCone and Garfield counties, MontanaJuly 20, 200128.0 mi (45 km)
  8. F1, Teton County, MontanaJuly 2, 196427.0 mi (43 km)
  9. EF2, Roosevelt County, MontanaJuly 15, 201323.0 mi (37 km)
  10. F2, McCone County, MontanaAugust 26, 195420.9 mi (34 km)
  11. F3, Yellowstone County, MontanaJune 16, 196520.6 mi (33 km)
  12. EF3, Sheridan County, MontanaJuly 26, 201018.0 mi (29 km)

The costliest

  1. EF2, Yellowstone County, MontanaJune 20, 2010$30 million
  2. F2, Fergus County, MontanaAugust 14, 1999$4.0 million
  3. EF3, Fallon County, MontanaJune 11, 2016$1.5 million
  4. EF2, Roosevelt County, MontanaJuly 15, 2013$500,000
  5. EF1, Phillips County, MontanaJune 29, 2011$300,000
  6. EF3, Sheridan County, MontanaJuly 26, 2010$300,000
  7. F1, Valley County, MontanaJune 21, 1999$250,000
  8. F0, Treasure County, MontanaAugust 23, 1998$200,000
  9. EF2, Powder River County, MontanaJune 21, 2010$150,000
  10. EF1, Powder River County, MontanaJune 21, 2010$107,000
  11. F0, Valley County, MontanaJuly 8, 2002$100,000
  12. F2, Fergus County, MontanaJuly 8, 2002$100,000

The biggest days in Montana

  1. July 5, 198811tornadoes
  2. July 8, 20026tornadoes
  3. July 20, 20015tornadoes
  4. August 14, 19995tornadoes
  5. August 23, 19985tornadoes
  6. August 26, 19955tornadoes
  7. June 21, 19915tornadoes
  8. June 8, 19885tornadoes
  9. June 25, 19755tornadoes
  10. June 28, 20184tornadoes
  11. June 21, 19994tornadoes
  12. August 13, 19934tornadoes

Every year

YearTornadoesDeathsInjuriesF4 and above
20244
20236
20223
20211
20203
20194
201810
20171
201667
201531
20148
20136
20123
20119
20101021
20094
20082
20075
20061
200510
20046
20036
200211
20019
200010
1999223
199811
19979
19968
199515
19948
1993193
19929
199130
19906
19896
1988202
19871
19864
19852
19845
1983411
19823
19813
19807
19795
197813
19776
19762
1975101
19732
19724
19718
19701
19692
19681
19662
196596
196461
19633
196210
1961211
19603
19593
195843
19571
19553
19544
19535
1952212

Every county in Montana

A tornado is counted once for every county its path crossed, so these add up to more than 444. Each county has a page of its own: every tornado that crossed it, year by year.

CountyTornadoesDeaths
Valley County44
Fergus County28
Yellowstone County21
Carter County18
Judith Basin County18
Powder River County18
Chouteau County17
Roosevelt County17
Dawson County15
Fallon County15
Phillips County15
Beaverhead County14
Cascade County13
Richland County13
Garfield County12
Rosebud County12
Big Horn County11
Custer County10
Daniels County10
Sheridan County102
McCone County91
Petroleum County8
Wibaux County81
Blaine County7
Hill County7
Toole County7
Wheatland County7
Lewis and Clark County6
Musselshell County6
Flathead County4
Gallatin County4
Lake County4
Liberty County4
Teton County4
Carbon County3
Glacier County3
Meagher County3
Prairie County3
Ravalli County3
Treasure County3
Granite County2
Madison County2
Missoula County2
Park County2
Powell County2
Sweet Grass County2
Golden Valley County21
Broadwater County1
Deer Lodge County1
Jefferson County1
Sanders County1
Stillwater County1
McKenzie County1

Nearby

Warnings in force in MontanaForecast for your townThe live radar over Montana

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.