The 2024 Chicagoland tornado outbreak was a tornado outbreak and severe weather event occurring on July 15, 2024. This weather event broke the daily record for tornado touchdowns in the Chicagoland forecasting area, where approximately 27–33 (the number is still being calculated at the time this article was published) tornados touched down in the Chicagoland area and other surrounding areas. The outbreak produced mostly weak EF0/EF1 tornados, though one EF2 tornado did drop down in the Channahon-Matteson area. The storm also produced intense straight line winds, most of which reached up to 80 mph and one reaching nearly 90 mph.^[1][2]

In the evening hours of July 15, 2024, a complex system of thunderstorms moving across the northern Midwestern United States produced supercell thunderstorms and a derecho, a rare weather event. Derechos form when humid air and downdrafts collide to create bow echos, which are curved or bowed thunderstorms. These bow echos eventually create a derecho, which are widespread and long-lasting powerful windstorms. The humid Midwest air mixing with an incoming cold front was the perfect scenario for a derecho to form. As the system moved east into Illinois, tornado watch alerts where issued in the late afternoon and early evening.^[1]

At 7:44 p.m., the first tornado warning was issued for Ogle County. This harmless tornado was an EF0 and was a short lived seven-minute tornado. By 8:00 p.m., two other EF0 tornados had dropped in Ogle County and Winnebago County. These first few tornados did relatively little damage and resulted in no fatalities.^[1]

For about a forty minute period, the storm moved northeast but did not produce any tornados, until 8:38 p.m., when a tornado dropped in Kane and DeKalb Counties. From about 8:45 to 9:45 p.m., approximately 20 tornadoes and strong wind bursts were recorded in surrounding areas. Most of the recorded tornadoes were EF0 and EF1 ratings, with minimal roof and tree damage.^[1]

After 9:45 p.m., approximately six other tornadoes touched down as the storm approached the Chicago, Illinois and Gary, Indiana. The final tornado dissipated at 10:20 p.m., near Valparaiso, Indiana. The storm took place over an approximate three hour timeline and the final tornado warnings were let up after 10:20 p.m., when it was confirmed that the system had passed completely.^[1]

The highest rated tornado was the Channahon-Matteson tornado, which was given an EF2 rating. The tornado lasted from 9:17 to 9:40 p.m. and moved on a 28.9-mile path. The maximum recorded wind speed of the tornado was about 120 mph and the maximum recorded width of the tornado was about 200 yards. The tornado resulted in two injures^[1] and was responsible for nearly five hours of traffic on Interstate 55, where drivers became trapped by debris and surrounded by unstable power lines which had fallen onto the highway. After the storm, ComEd teams worked to clear the debris, closing a nearly seven mile stretch of the road for three days. After three days, ComEd reported that nearly 18,000 residents of the area were still without power due to this tornado. Other damage included crop destruction, tree damage, and roof damage.^[3]

The information listed above represents data that is known as of 25 July 2024. This data chart may eventually be inaccurate if new data emerges.

Some of the confirmed tornadoes listed above have unknown damage. This may mean that that specific tornado had little to no damage, unreported damage, or damage that has yet to be recorded/released.

• 1990 Plainfield Tornado
• 1967 Oak Lawn Tornado Outbreak
• List of recorded American tornadoes