Tornadoes in the U.S. state of Illinois are common, with 3,214 tornadoes occurring within state boundaries since 1950. These tornadoes have collectively resulted in 235 deaths.

Climatology

Illinois' climate is relatively average, and is only ideal for the formation of tornadoes in certain parts of the year, especially February, March and May. Warm air from the Southern United States can reach up into the Southern Illinois, resulting in tornadic storms. Illinois' proximity to Lake Michigan also results in cold air moving toward the Ohio Valley, creating the "hot-cold" effect seen in the traditional Tornado Alley. Illinois has had large tornado outbreaks in the past, including the tornado outbreak sequence of December 18–20, 1957 and the 1967 Oak Lawn tornado outbreak.

Illinois is vulnerable to tornadoes with an average of 35 occurring annually, which puts much of the state at around 5 tornadoes per annually. Peak tornado activity occurs between February and May, but storms can and have produced tornadoes in the winter.

Events

Pre-1950

April 18, 1880 – A violent F4 tornado tracked through Winnebago County, destroying multiple farms and killing one person before crossing the state line into Wisconsin, where more damage to homes occurred. An F2 tornado hit Lyndon, destroying farmsteads. An FU tornado destroyed multiple homes near Greenville. Tornado outbreak of April 24, 1880 – One of only two F5-strength tornadoes to affect central or southeast Illinois. This tornado touched down 9 miles southwest of Taylorville, then moved northeast through Taylorville (Langley/Langleyville) before lifting northeast of Sharpsburg. Bodies of people and cattle were reportedly carried over a half-mile. 6 reported fatalities and 33 injuries. February 19, 1884 – An FU tornado struck Caseyville,Fort Wayne Daily Gazette, Fort Wayne, Indiana. February 22, 1884. and another FU tornado caused an unknown amount of damage in Metropolis. March 27, 1890 – A relatively destructive F2 tornado initially touched down in Missouri before crossing the state line into Randolph County. No known injuries occurred. Another F2 tornado touched down in Missouri, crossing the state border into Sunfield, killing 3 people. An F2 tornado killed one person in Centreville. A violent F4 tornado touched down in Missouri before moving into Jackson County, killing 7 people and destroying multiple structures. An F2 tornado also tracked through areas south of McClure. Another F4 tornado also touched down in Missouri, before tracking through Alexander, Union, Johnson and Williamson counties, killing 2 people along its path. A long-lived F3 killed 2 people in Washington County, and an F4 tornado moved through Massac and Pope counties, killing 21 or more people and injuring over 200. An F2 tornado hit Olney, damaging or destroying an estimated 33 homes and injuring 5. Another F2 tornado tracked across Wayne and Clay counties, injuring 10 people. The final tornado to occur in Illinois during the outbreak was an F2 that tracked though White County, killing one person and injuring 10 others. May 25, 1896 – A violent and destructive F4 tornado moved through Ogle County, destroying a church and killing 4 people.Grazulis, Significant, p. 676 An F2 tornado touched down south of Byron, destroying a farm and damaging trees. A long-tracked F3 tornado moved from Davis Junction to Irene, killing 3 people and destroying 11 farms. A brief but destructive F3 tornado touched down in Edison Park, Chicago, damaging or destroying 36 buildings. May 27, 1896 – A catastrophic and devastating F4 tornado moved through St. Louis and East St. Louis, killing over 255 people and injuring 1,000 or more. It is the third-deadliest tornado in United States history,Mary K. Dains, "The St. Louis Tornado of 1896." Missouri Historical Review (1972) 66#3 pp 431–445. and caused over $10 million (1896 USD) in damages. An extremely violent F4 tornado destroyed farms in Washington and Jefferson counties, killing 14 people. Another F4 tornado tracked through St. Clair and Clinton counties, killing 24. The final tornado in Illinois of the outbreak moved through Jefferson County, killing 3 people and damaging crops and other structures at EF3 intensity. April 29, 1909 – A violent F4 tornado tore through Saline and Gallatin counties, killing five people and causing heavy damage in Texas City. The tornado had a maximum width of 200 yards. May 26, 1917 – An FU tornado briefly touched down near Pleasant Hill, causing an unknown amount of damage but no injuries. An extremely violent high-end F4 tornado moved across Illinois, killing 101 people and injuring a further 638. The hardest-hit community was Mattoon, where almost 500 buildings were destroyed. The tornado had maximum windspeeds of around 300 mph. A high-end F3 tornado tracked through Coles and Clark counties, destroying farm and injuring 15 people. Another F4 tornado touched down in Will County before crossing the state line into Indiana, killing 3 people along its 33-mile track. A brief FU tornado killed one person in Randolph County, and another FU tornado caused $80,000 (1917 USD) in damages to Willisville. An FU tornado caused minimal damage in Jackson County. May 27, 1917 – A destructive F3 tornado touched down in Missouri, before crossing into Randolph County. One person was killed near Chester. May 30, 1917 – Two separate tornadoes touched down in Ste. Genevieve County in Missouri before crossing the state line into Randolph County, inflicting F2 and F3 damage to at least 10 structures. March 18, 1925 – An extremely destructive and incredibly deadly F5 tornado moved through three states, one being Illinois. The tornado killed 695, making it the deadliest tornado in United States history. It was particularly violent in Williamson County, and 102 people were killed in West Frankfort. May 9, 1927 – An F3 tornado killed one person and injured 12 others in Schuyler and Fulton counties. An F2 tornado briefly touched down near Eden, deroofing a farmhouse but caused no fatalities. Another high-end F3 tornado tracked 45 miles across Christian and Macon counties, killing one person. A short-lived F2 tornado destroyed several barns near Owaneco. A destructive F3 tornado damaged homes and injured 21 people in Williamson County, and an F2 tornado killed 2 people in Massac County. September 29, 1927 – An F3 tornado moved through East St. Louis, killing 79 people and injuring a further 550. Losses from the tornado totaled $53 million (1927 USD). An F2 tornado deroofed a home south of Morrisonville, and a tornado inflicted F3 damage to structures in Cowden, killing two people and causing $10,000 (1927 USD) in damages. An F2 tornado destroyed and damaged several barns in Edgar County, and an FU tornado was reported in Conlogue. March 16, 1942 – A violent F4 tornado moved through Piatt, Champaign and Vermilion counties, destroying over 40 structures and killing 12 people. An F2 tornado damaged 13 farmsteads in Fulton County, and another F2 tornado damaged 10 farmsteads in Knox and Peoria counties. A destructive F5 tornado killed 7 people in or around Lacon, and losses from the tornado totaled $600,000 (1942 USD). This tornado is the most recent F5 or EF5 tornado to hit Central Illinois. An F2 tornado killed two people in Lincoln County, and an FU tornado was reported west of Findlay. April 12, 1945 – An F2 tornado tracked through portions of Missouri before crossing the state line into Adams County, causing $3 million (1945 USD) in damages. Another F2 tornado moved through Hancock and McDonough, causing $200,000 (1945 USD) in damages but killing nobody. An F2 tornado hit Industry, causing minimal damage to structures. An F2 tornado hit Missouri, before dissipating shortly past the state line in Quincy. 11 people were injured, and the tornado caused $250,000 (1945 USD) in damages.

1950–1959

March 27, 1950 – A strong F2 tornado tracked across McLean County, causing $2,500 (1950 USD) in damages. June 27, 1951 – A high-end F3 tornado moved through Logan and Macon counties, damaging various structures along its 9.6-mile path. Another F3 tornado tracked across Logan and De Witt counties, killing one person and causing $2.5 million (1951 USD) in damages. May 24, 1952 – An F1 tornado tracked down a runway at Scott Air Force Base, damaging 11 aircraft and destroying a building. Losses from the tornado totaled $25,000 (1952 USD). March 14, 1953 – A long-tracked and destructive F2 tornado moved through Washington, Jefferson and Marion counties, destroying one home and damaging various structures along its 42.3-mile track. April 7, 1954 – An F3+ tornado tracked through areas southwest of Saunemin, and an F3 tornado destroyed 38 homes and killed one person in Kankakee County. May 26, 1955 – An F2 tornado briefly tracked through areas east of Coatsburg. Another F2 touched down south of Pekin, causing minimal damage. An F1 moved through Burbank, and a long-tracked tornado inflicted F1 damage to structures in Kankakee and Will counties. December 18, 1957 – An intense F3 tornado moved through Randolph and Perry counties, causing $25,000 (1957 USD) in damages, and another tornado damaged or destroyed 24 or more homes at F3 intensity in Willisville. A short-lived but strong F2 tornado touched down in Northern Roxana, damaging nine buildings and injuring one person. A brief F1 tornado caused minimal damage in Mason City, and an F3 tornado hit the crossroads of Illinois Routes 154–150, damaging six homes and causing $250,000 (1957 USD) in damages. An F2 tornado moved for 4.5 miles across Jefferson County, deroofing multiple buildings and injuring two people. A violent F4 tornado touched down south of Roaches, reaching a maximum width of 250 yards and killing one person. Losses from the tornado totaled $2.5 million (1957 USD). An F2 tornado moved through Jackson County, damaging multiple properties but killing nobody. A weak and relatively short-tracked F33 tornado touched down in Missouri before crossing state lines into Randolph County, causing $25,000 (1957 USD) in damages to freight cars and buildings. An F2 tornado hit the outskirts of Mount Vernon, damaging 12 buildings. A destructive and violent F5 tornado hit Sunfield, completely destroying the town and killing 3 people. The tornado injured 6, and caused up to $250,000 (1957 USD) in damages. Another violent and long-tracked tornado inflicted F4 damage to multiple structures in Jackson, Williamson and Franklin counties. Losses from the tornado totaled $4.5 million (1957 USD), and up to 200 people were injured. An F3 tornado tracked 19.6 miles in Wayne and Clay counties, injuring one person and damaging 20 structures. A brief F2 tornado touched down in Carbondale, and an F3 tornado damaged four farmsteads in Jasper County. Another brief F3 tornado moved through Dahlgren, damaging or destroying several homes. A long-lived F3 tornado tracked across Hamilton, White and Edwards counties, damaging 20 farmsteads and injuring 4 people. A very brief tornado touched down in Johnson County, damaging 4 buildings, including a church. An F1 tornado caused minimal damage along a 3-mile track in Vermilion County. December 19, 1957 – A brief F2 tornado damaged numerous structures in Jefferson County, and another F2 tornado damaged a barn south of Harrisburg. February 10, 1959 – A violent F4 tornado initially touched down in St. Louis, Missouri before crossing the state line into Brooklyn. 21 were killed, 345 were injured, and the tornado caused an estimated $50.25 million (1959 USD) in damages to the Greater St. Louis area. A weak but long-lived F1 tornado moved through Washington, Jefferson and Marion counties, damaging 10 farmsteads. Another F1 tornado briefly touched down north of Palestine, injuring one person and damaging 10 structures.

1960–1969

April 30, 1960 – An F1 tornado briefly moved through Atlanta, causing an estimated $2,500 (1960 USD) in damages.