+Tornadoes per state/provinceStateTotalF0F1F2F3F4Alabama936000Arkansas311100Colorado110000Illinois281214200Indiana26137420Iowa523812110Kansas462912320Kentucky1785310Maryland211000Michigan963000Minnesota330000Mississippi211000Missouri35237311Nebraska664518201New York101000North Dakota211000Ohio422000Oklahoma251111210Ontario411200Pennsylvania210100South Dakota19190000Tennessee606000Texas15132000Virginia532000West Virginia110000Wisconsin440000Wyoming110000Totals389 Each tornado is classed per state based on its starting location. The tornado outbreak sequence of May 2004 produced several tornado outbreaks between May 21 and May 31, 2004, across mostly the Midwestern and Southern United States as well as southern Ontario, including three major outbreaks on May 22, May 24 and May 29–30. Overall, the sequence produced 389 tornadoes, which makes it one of the most productive tornado outbreak sequences in history.
The Hallam, Nebraska tornado outbreak on May 22 produced nearly 60 tornadoes across mostly Nebraska and Iowa including an F4 that tore through the town Hallam situated halfway between Lincoln and Beatrice. It was recorded as the largest tornado ever with a width of and one person was killed. However, in May 2013 it was passed by the El Reno, Oklahoma tornado with a width of 2.6 miles wide. On May 24, another tornado outbreak took place across the central United States, with about 50 tornadoes confirmed in Kansas, Illinois, Nebraska and Missouri. One person was killed in western Illinois near Winchester west of Springfield. A smaller outbreak on May 27 produced a damaging tornado in the city of Lexington in northern Kentucky.
The Memorial Day Weekend outbreak produced one of the largest tornado outbreaks on record from May 29, 2004 to the early morning hours of May 31, 2004. During the Memorial Day Weekend, 168 tornadoes touched down from the Midwestern United States from the Dakotas to Oklahoma eastward towards the Ohio and Tennessee Valleys from Ohio and Indiana southward towards Alabama. This outbreak has been compared with the April 3–4, 1974 Super Outbreak in terms of number of tornadoes, but had much fewer strong to violent tornadoes, with only one violent tornado in Missouri and 16 other strong tornadoes, while there were 30 violent and 66 strong tornadoes during the record-breaking event in 1974. At least five people were killed by this outbreak across two states, including four in Missouri and one in Indiana, but the death toll is much lower than the 315 or more deaths recorded during the 1974 event.
Confirmed tornadoes
May 21 event
F#LocationCounty Time (UTC)Path lengthDamageIowa F0Holland area Grundy 1928 3 miles (4.8 km)Brief touchdown with no damage. F1NE of Holland Grundy 1938 3.5 miles (5.6 km)Weak tornado with little or no damage. F0E of Holland Grundy 1949 0.5 mile (0.8 km)Brief touchdown with no damage. F0NW of Ivester Grundy 2015 0.5 mile (0.8 km)Brief touchdown with no damage. F0N of Waterloo Black Hawk 2021 0.3 mile (0.5 km)Brief touchdown with no damage. F0NW of Holland Grundy 2022 0.5 mile (0.8 km)Brief touchdown with no damage. F0SE of Newhall Benton 2105 0.1 mile (0.15.6 km)Brief touchdown with no damage. F0NW of Vinton Benton 2107 0.1 mile (0.16 km)Brief touchdown with no damage. F1NW of Atkins Benton 2113 1.7 miles (2.7 km)Tornado damaged trees and farms, some heavily. Outbuildings were damaged, and one was completely destroyed. F3Palo area Linn 2122 3 miles (4.8 km)Tornado initially caused damage to a farm two miles southwest of Palo where a garage and three outbuildings were destroyed. As it approached Palo, another farm was severely damaged. The roof and walls were torn off a house, and a car was lofted 50 feet. The tornado continued across the southern edge of Palo, where it destroyed a mobile home before dissipating. F0Vinton area Benton 2144 unknownBrief touchdown with no damage F1E of Martelle Jones 2206 6 miles (9.6 km)A cattle shed and a mobile home were destroyed while houses and outbuildings sustained minor damage. Trees were damaged as well. F1SE of Royal Clay 2212 1 mile (1.6 km)Tornado destroyed a farm house and several other buildings on a farm. F1W of Rolfe Pocahontas 2300 5 miles (8 km)Weak tornado with little or no damage. F2Bradgate area Pocahontas, Humboldt 2308 12.5 miles (20 km) Approximately 75% of the buildings in Bradgate were damaged or destroyed by this half-mile-wide tornado. Outbuildings, light structures, and garages were heavily damaged or destroyed. Large trees were snapped, and 15 people were injured. F0W of Cornelia Wright 0030 0.2 mile (0.32 km)Brief touchdown with no damage.Ohio F0SE of Olivesburg Richland 2002 unknownBrief touchdown with no damage.West Virginia F0N of Arden Berkeley 0114 3 miles (4.8 km)Damage limited to trees.Nebraska F1N of Hadar Pierce 0120 1.5 miles (2.4 km)A garage, a farm, and a few farm outbuildings were damaged. The tornado also downed power lines near Hadar, knocking out the power to part of town. F0S of Ainsworth Brown 0144 0.2 mile (0.32 km)Brief touchdown with no damage. F1SE of Wayne Wayne 0220 0.5 mile (0.8 km)One barn and six outbuildings were severely damaged or destroyed. One house sustained lesser damage. F0NW of Bartlett Garfield 0313 0.2 mile (0.32 km)Brief touchdown with no damage.South Dakota F0W of Gayville Yankton 0220 0.1 mile (0.16 km)Brief touchdown with no damage. Sources: , NCDC Database- May 21, 2004
May 22 event