CHICAGO — Storm season is in full swing across Illinois and that means it is time for many to prepare their emergency kits and put together a tornado safety plan. But as severe weather brings the risk of twisters to the state, some may be wondering if Illinois is in Tornado Alley.
This year’s storm season follows an unusually active year. The number of confirmed tornadoes in 2023 broke the state’s yearly average of around 50 twisters by a wide margin.
The Insurance Information Institute said Illinois topped the list as the U.S. state with the most tornadoes in 2023, with 136 touching down. Alabama came in at second with 101 tornadoes.
According to the National Weather Service (NWS), nearly 80% of all tornadoes in Illinois occur between April 1 and June 30, and parts of the state have already been pelted by intense storms this year.
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NAPERVILLE, ILLINOIS – JUNE 21: A garage was destroyed on the 7500 block of Gladstone Drive after a tornado came through the area on June 21, 2021 in Naperville, Illinois. Hundreds of homes were damaged when a tornado swept through the Chicago suburbs. (Photo by Jon Durr/Getty Images) -
NAPERVILLE, ILLINOIS – JUNE 21: Debris is piled up after a garage was destroyed on the 7500 block of Gladstone Drive on June 21, 2021 after a tornado came through the area in Naperville, Illinois. Hundreds of homes were damaged when a tornado swept through the Chicago suburbs. (Photo by Jon Durr/Getty Images) -
NAPERVILLE, ILLINOIS – JUNE 21: A car is flipped on its side in a parking lot on the 7500 block of Gladstone Drive on June 21, 2021 after a tornado came through the area in Naperville, Illinois. (Photo by Jon Durr/Getty Images) -
WOODRIDGE, ILLINOIS – JUNE 21: A house on the 2700 block of Jonquil Lane suffered severe damage on June 21, 2021 after a tornado came through the area in Woodridge, Illinois. (Photo by Jon Durr/Getty Images)
Where is Tornado Alley?
The term “Tornado Alley” has always had a fairly loose definition. The first recorded use of the term was back in 1952 when it was used by U.S. Air Force meteorologists as the title of a research project.
The research project sought to analyze tornadoes in Texas, Louisiana, Oklahoma, Kansas, South Dakota, Iowa and Nebraska.
Since then, the term has taken on many definitions, but meteorologically, the areas that make up Tornado Alley are situated in the ideal location for the formation of supercell thunderstorms, which are often what produce tornadoes.
According to the National Severe Storms Laboratory (NSSL), the term is just a nickname for an area that has traditionally experienced a high volume of tornadoes and it is not clearly defined.
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FAIRDALE, IL – APRIL 10: Crews search through the town for unaccounted people the morning after a tornado swept through the town on April 10, 2015 in Fairdale, Illinois. According to reports, 11 people were injured and one person was killed when tornadoes and thunderstorms passed through the northwestern suburbs of Chicago. (Photo by Jon Durr/Getty Images) -
FAIRDALE, IL – APRIL 10: Houses and property in ruin the morning after a tornado swept through the town the previous day on April 10, 2015 in Fairdale, Illinois. According to reports, 11 people were injured and one person was killed when tornadoes and thunderstorms passed through the northwestern suburbs of Chicago. (Photo by Jon Durr/Getty Images) -
ROCHELLE, IL – APRIL 10: The restaurant Grubstakers was damaged by a tornado the previous night, on April 10, 2015 in Rochelle, Illinois. According to reports, 11 people were injured and one person was killed when tornadoes and thunderstorms passed through the northwestern suburbs of Chicago. (Photo by Jon Durr/Getty Images) -
ROCHELLE, IL – APRIL 10: Wreckage on IL-64 after a tornado came through the previous night, on April 10, 2015 in Rochelle, Illinois. According to reports, 11 people were injured and one person was killed when tornadoes and thunderstorms passed through the northwestern suburbs of Chicago. (Photo by Jon Durr/Getty Images) -
COAL CITY, IL – JUNE 23: Debris lay in a retention pond off of S Carbon Hill Road after a tornado struck the previous day on June 23, 2015 in Coal City, Illinois. (Photo by Jon Durr/Getty Images) -
COAL CITY, IL – JUNE 23: A playground set lays on the ground in the backyard of a home on W Daisy Place after a tornado struck the previous day on June 23, 2015 in Coal City, Illinois. (Photo by Jon Durr/Getty Images) -
COAL CITY, IL – JUNE 23: A pickup truck drives through a flooded roadway on W Daisy Place after a tornado struck the previous day on June 23, 2015 in Coal City, Illinois. (Photo by Jon Durr/Getty Images)
Is Tornado Alley shifting east?
Last year, a state climatologist indicated that “Tornado Alley” may be shifting eastward to include Illinois.
A study from Northern Illinois University, which examined tornado data dating back to the early 1970s, found that tornado frequency may be shifting to the east, and while the traditional boundaries of Tornado Alley still see the greatest frequency of twisters, there has been a decrease in the number of tornadoes in the area and an increase in tornadoes to the east, in Mississippi, Alabama, Arkansas, Missouri, Illinois, Indiana, Tennessee, and Kentucky.
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Residents survey tornado damage on Wednesday, March 1, 2017 in Naplate, Ill. (Zbigniew Bzdak/Chicago Tribune/Tribune News Service via Getty Images) -
Residents survey tornado damage on Wednesday, March 1, 2017 in Naplate, Ill. (Zbigniew Bzdak/Chicago Tribune/Tribune News Service via Getty Images) -
Residents survey tornado damage on Wednesday, March 1, 2017 in Naplate, Ill. (Zbigniew Bzdak/Chicago Tribune/Tribune News Service via Getty Images) -
Residents survey tornado damage on Wednesday, March 1, 2017 in Naplate, Ill. (Zbigniew Bzdak/Chicago Tribune/Tribune News Service via Getty Images)
Is Illinois in Tornado Alley?
While some definitions of Tornado Alley do not include the state, the boundaries of Tornado Alley are debatable and the term is not recognized by the National Weather Service.
Most common definitions now consider Tornado Alley to be an area that extends from Texas, through Oklahoma, Kansas, Nebraska, South Dakota, Iowa, Minnesota, Wisconsin, Illinois, Indiana, Missouri, Arkansas, North Dakota, Montana, Ohio, and some portions of Colorado and Wyoming.
So while Illinois may not have always been considered to be a part of Tornado Alley, the increasing frequency of twisters in the state has caused a bit of a shift in the definition.
