An F5 tornado strikes the Illinois cities of Plainfield and Joliet, killing 29 people.

The 1990 Plainfield tornado was a devastating tornado that struck Plainfield, Illinois in the Chicago metropolitan area during the afternoon of Tuesday, August 28, 1990. The violent tornado killed 29 people and injured 353. It is the only F5/EF5 rated tornado officially recorded in August in the United States, and the only F5 tornado to strike the Chicago area. There are no known videos or photographs of the tornado itself; however, in 2011, a video surfaced online showing the supercell that spawned the tornado. The Plainfield tornado was part of a small outbreak that produced several tornadoes in the Northern United States, specifically Kansas, and the Canadian province of Ontario.

Illinois is a state in the Midwestern region of the United States. It borders Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash and Ohio rivers to its south. Of the fifty U.S. states, Illinois has the fifth-largest gross domestic product (GDP), the sixth-largest population, and the 25th-most land area. Its capital city is Springfield in the center of the state, and the state's largest city is Chicago in the northeast.

Plainfield is a village in Will and Kendall counties in the U.S. state of Illinois. The population was 44,762 at the 2020 census. It is part of the Chicago metropolitan area.

Joliet is a city in Will and Kendall counties in the U.S. state of Illinois, located 40 miles (64 km) southwest of Chicago. It is the county seat of Will County. It had a population of 150,362 at the 2020 census, making it the third-most populous city in Illinois.