Tornadoes are among the most devastating and awesome local storms that occur on Earth. The United States has the dubious distinction of having the greatest frequency and the most severe tornadoes. Tornadoes have the power to lift railroad cars and sail them many yards through the air. The power of their winds can make deadly missiles of loose objects, including broken glass. Even pieces of straw have been found embedded in trees and boards after a tornado.
During the winter months (December through February) tornado activity is concentrated in the southeast U.S. and along the Gulf Coast. As spring (March/May) progresses, tornado occurrence moves north and west across the central Mississippi and Ohio River Valleys. By summer (June/August) the potential threat of tornadoes has spread across the continental United States and Southern Canada. During autumn (September/November), tornadic activity gradually retreats to the south and southeast sections of the country and is often associated with hurricanes.
This seasonal drift is principally caused by the increase of warm, Gulf of Mexico moisture into the central part of the country during spring and summer, decreasing during the fall and winter. Severe weather and even tornadoes can occur when this warm and moist intersects a cold-air boundary and is overtopped by strong winds aloft.
Minnesota lies along the north edge of the region of maximum tornado occurrence in the United States, often referred to as Tornado Alley.
In Minnesota, tornadoes generally occur May through September, but some years see them occurring much earlier and/or later in the season. The record earliest-in-the-season tornadoes in Minnesota were the three that occurred on March 6, 2017, which broke the previous record from March 18, 1968, north of Truman in Martin County. The seasonally-latest reported tornadoes in Minnesota were on December 15, 2021 during a major regional severe weather outbreak (see image at right). This outbreak broke the previous record for late-season tornadoes by nearly one month; it had been November 16, 1931, when a single tornado struck east of Maple Plain in Hennepin County.
Historically and statistically, June is the month of greatest frequency with July not far behind. May has the third greatest frequency, followed closely by August. Over 85% of all tornadoes in Minnesota have occurred between May and August.
Tornadoes are most common between 2:00 PM and 9:00 PM, but can and do occur at any time of the day, or night.
Many of the deadly and damaging tornadoes occur in groups or outbreaks that often last from 3 to 12 hours. One of the worst such outbreaks in Minnesota occurred on June 17, 2010, when 48 tornadoes affected 22 counties in northwestern, west-central, central, east-central, south-central, and southeastern Minnesota over a period of six hours. Other noteworthy large-area outbreaks occurred June 16, 1992 (which included the state's most recent F5 tornado, in Chandler); June 28, 1979, when 16 tornadoes slashed across the state from northwest to southeast; August 6, 1969, when powerful and massive tornadoes devastated parts of northern Minnesota; and the April 30, 1967 "Black Sunday" outbreak in southern and southeastern Minnesota.
Minnesota Tornado Statistics
1950 - 2020 | Totals | Annual Average |
---|---|---|
Tornadoes | 2052 | 46 (1991 to 2020) |
Tornado Deaths (last death was 2020) | 100 | |
Tornado Injuries | 1985 |
Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Total | |
---|---|---|---|---|---|---|---|---|---|---|
Totals | 23 | 27 | 170 | 426 | 351 | 199 | 84 | 21 | 5 | 1306 |
Average | 0.8 | .9 | 5.7 | 14.2 | 11.7 | 6.6 | 2.8 | 0.7 | 0.2 | 46 |
Percent | 1.8 | 2.1 | 13.0 | 32.6 | 26.9 | 15.2 | 6.4 | 1.6 | 0.4 | 100 |
One Year | 113 in 2010 |
One Month | 71 in June 2010 |
One Day | 48 on June 17, 2010 |
Memorable Minnesota Tornadoes
Location | Date | Time | Deaths | Injuries |
---|---|---|---|---|
Ft. Snelling | 4/19/1820 | 11:00 PM (est.) | 0 | 0 |
Rochester | 8/21/1883 | 6:36 PM | 37 | 200 |
St. Cloud/Sauk Rapids | 4/14/1886 | 4:00 PM | 72 | 213 |
Lake Gervias (Ramsey County) | 7/13/1890 | 5:30 PM | 6 | 30 |
Minneapolis/St. Paul | 8/21/1904 | 7:30 PM | 14 | unknown |
8/21/1918 | 9:20 PM | 36 | 225 | |
Fergus Falls | 6/22/1919 | 4:45 PM | 57 | 200 |
Austin | 8/20/1928 | 4:10 PM | 6 | 60 |
6/18/1939 | 2:00 PM | 9 | 222 | |
Mankato/North Mankato | 8/17/1946 | 5:40 PM | 11 | 100 |
Wells | 8/17/1946 | 6:50 PM | 0 | 30 |
Southeast Minnesota | 5/10/1953 | 4:00-5:00 PM | 7 | 19 |
Fargo/Moorhead | 6/20/1957 | 6:40 PM | 10 | 103 |
Western and Northern Twin Cities | 5/6/1965 | 6:00-9:00 PM | 13 | 683 |
South Central Minnesota | 4/30/1967 | 6:00-8:00 PM | 13 | 65 |
Tracy | 6/13/1968 | 7:02 PM | 9 | 125 |
Outing | 8/6/1969 | 4:02 PM | 12 | 70 |
Gary | 7/5/1978 | 1:56 AM (CST) | 4 | 38 |
Lake Harriet/Har Mar | 6/14/1981 | 3:49-4:15 PM | 1 | 83 |
St. Anthony-Apache Plaza | 4/26/1984 | 8:33-8:41 PM | 1 | 52 |
Brooklyn Park | 7/18/1986 | approx: 3:47-4:27PM | 0 | 0 |
Chandler | 6/16/1992 | 4:00 PM | 1 | 35 |
Littlefork | 8/9/1993 | 1:35 AM | 2 | 0 |
Comfrey/St. Peter | 3/29/1998 | 4:30 PM | 1 | 16 |
7/25/2000 | 4:57 PM | 1 | 15 | |
8/24/2006 | 5:30-6:25PM | 1 | 37 | |
9/16/2006 | 9:58 PM | 1 | 0 | |
5/25/2008 | 4:55 PM | 1 | 9 | |
Wadena and many Minnesota locations | 6/17/2010 | various | 3 | 45 |
5/22/2011 | 2:13 PM | 1 | 48 | |
9/20/2018 | various | 0 | 1 | |
Grant & Otter Tail County (west-central MN) | 7/8/2020 | 5:08 PM | 1 | 2 |
South central and southeast Minnesota) | 12/15/2021 | between 7-8:30 PM | 0 | unknown |
More Tornado Information
- Minnesota Tornadoes by County 1950-2022
- Annual Severe Weather Report Summary
- Minnesota Tornadoes 2019 from the National Weather Service
- List
- Minnesota Tornadoes 2018 from the National Weather Service
- Download map
- List
- details
- Minnesota Tornadoes 2017 from the National Weather Service
- Download map
- Minnesota Tornadoes 2016 from the National Weather Service
- List
- Minnesota Tornadoes 2015 from the National Weather Service
- Download map
- List
- Past Minnesota Tornadoes from the National Weather Service
- Minnesota Tornado Statistics (1950-1995) from the Tornado Project
- Worst Minnesota Tornadoes (1879-1995) from the Tornado Project
- Storm Report Data for Past Days (National Weather Service Storm Prediction Center)
- Storm Events Database (National Climatic Data Center)
- National Weather Service Storm Prediction Center
- The Online Tornado FAQ (National Weather Service Storm Prediction Center)
- The Tornado Project
- List of North American Tornadoes and Tornado Outbreaks (Wikipedia)
- Smithsonian Interactive Tornado Page
- National Severe Storms Laboratory
- Reshaping the Tornado Belt: The Grand Forks/East Grand Forks Tornado of June 16, 1887
- Tornado Survival Guide