The 2007 Midwest flooding was a major flooding event that occurred in the Midwestern United States in the third week of August 2007. While Hurricane Dean was affecting the Yucatán Peninsula and the Gulf of Mexico, and Tropical Storm Erin was affecting Oklahoma and Texas, a persistent storm system hung over the Midwest for several days, causing repeated flash flooding in the US states of Illinois, Indiana, Iowa, Minnesota, Ohio, and Wisconsin. Cool Canadian air clashed with large quantities of warm moist air from the Gulf, producing torrential rains along a stationary front. 5 deaths across the central United States were attributed to the resulting flooding. Seven Minnesota counties, eight Ohio counties, fourteen counties in Wisconsin, and seven counties in Illinois were declared Federal Disaster Areas.

McHenry County is a county located in the U.S. state of Illinois. According to the 2020 Census, it had a population of 310,229, making it the sixth-most populous county in Illinois. Its county seat is Woodstock. McHenry County is one of the five Illinois collar counties in the Chicago-Naperville-Elgin, IL-IN-WI Metropolitan Statistical Area. Long known as a center of recreation along with agriculture in the western portion, it has more recently experienced rapid rates of suburbanization, exurbanization and urbanization, but the western portions of the county remain primarily agricultural and rural.