Dear Tom,
How many tornadoes have struck in the Chicago area?
Tommy Narmaldson,

Dear Tommy,
Between 1876 and 2021 there were 89 tornadoes of (E)F2 or greater strength in the eight-county metropolitan area. (The metropolitan area consists of the following eight counties: McHenry, Lake, DuPage, Cook, Kendall, Will and Lake County (Indiana).

Tornadoes of EF2 or greater strength are termed “significant tornadoes”. Approximately 70 percent of tornadoes are classified as “weak” (EF0 and EF1) with winds less than 113 mph. The wind circulations of these weak tornadoes are often disrupted as they encounter areas of tall buildings in the city.

Within Chicago city limits, a tornado of F2 intensity moved from 91st Street and Hoyne Avenue to 68th Street and Lake Michigan on March 4, 1961, killing one person and injuring 115 others. However, the largest tornadoes have occurred in the suburbs.

Most notable storms included F4 tornadoes in Belvidere and Oak Lawn on April 21, 1967, and the area’s only known F5 storm, the Plainfield tornado of August 28, 1990 that moved from Oswego to Joliet. Most recently, an EF3 tornado struck Naperville, Woodridge, Darien and Burr Ridge on June 21, 2021. Eight people were injured and 225 structures were damaged, many severely. Winds were estimated at 136 to 165 mph.