The Midwestern United States, also referred to as the Midwest or the American Midwest, is one of four census regions of the United States Census Bureau (also known as "Region 2"). It occupies the northern central part of the United States. It was officially named the North Central Region by the Census Bureau until 1984. It is between the Northeastern United States and the Western United States, with Canada to the north and the Southern United States to the south.

The Census Bureau's definition consists of 12 states in the north central United States: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. The region generally lies on the broad Interior Plain between the states occupying the Appalachian Mountain range and the states occupying the Rocky Mountain range. Major rivers in the region include, from east to west, the Ohio River, the Upper Mississippi River, and the Missouri River. The 2020 United States census put the population of the Midwest at 68,995,685. The Midwest is divided by the Census Bureau into two divisions. The East North Central Division includes Illinois, Indiana, Michigan, Ohio, and Wisconsin, all of which are also part of the Great Lakes region. The West North Central Division includes Iowa, Kansas, Minnesota, Missouri, North Dakota, Nebraska, and South Dakota, several of which are located, at least partly, within the Great Plains region.

Chicago is the most populous city in the American Midwest and the third most populous in the United States. Chicago and its suburbs, together called Chicagoland, form the largest metropolitan area with 10 million people, making it the fourth largest metropolitan area in North America, after Greater Mexico City, the New York Metropolitan Area, and Greater Los Angeles. Other large Midwestern cities include (in order by population) Columbus, Indianapolis, Detroit, Milwaukee, Kansas City, Omaha, Minneapolis, Wichita, Cleveland, St. Paul, St. Louis, and Cincinnati. Large Midwestern metropolitan areas include Metro Detroit, MinneapolisSt. Paul, Greater St. Louis, Greater Cincinnati, the Kansas City metro area, the Columbus metro area, and Greater Cleveland.

The 2010 New Year's Eve tornado outbreak was a three-day-long tornado outbreak that impacted the central and lower Mississippi Valley from December 30, 2010 to January 1, 2011. Associated with a low pressure system and a strong cold front, 37 tornadoes tracked across five states over the length of the severe event, killing nine and injuring several others. Activity was centered in the states of Missouri and later Mississippi on December 31. Seven tornadoes were rated EF3 on the Enhanced Fujita Scale; these were the strongest during the outbreak. Non-tornadic winds were recorded to have reached as high as 80 mph (130 km/h) at eight locations on December 31, while hail as large as 2.75 in (7.0 cm) was documented north-northeast of Mansfield, Missouri. Overall, damage from the outbreak totaled US$123.3 million, most of which was related to tornadoes.The United States Storm Prediction Center first noted a possible New Year's Eve severe weather event as early as December 25, 2010. These forecasts gained confidence as the event approached, with a focus on the Ozarks and adjacent areas. Supercells developed in this area during the night of December 30 and tracked across central Missouri, producing several tornadoes and large hail. However, the bulk of activity during the outbreak was a result of a long line of supercells that tracked from Oklahoma to Illinois, producing five EF3 tornadoes. One of these tracked through northwestern Arkansas, killing four. Another tore through eastern sections of Fort Leonard Wood in Missouri, destroying 159 homes and causing US$90 million in damage, making it the costliest tornado of the outbreak. A separate cluster of storms later developed in Louisiana before tracking into Mississippi, producing several tornadoes across southern and central regions of the state on January 1.