Chicago extends westward on a plain along the southwest shore of Lake Michigan. The climate is continental, with frequently changing weather bringing temperatures that range from relatively warm in the summer to relatively cold in the winter. Temperatures of 96 degrees or higher occur during summers; winters can register a minimum low of minus 15 degrees. Snowfall near the lakeshore is usually heavy because of cold air movement off Lake Michigan. Summer thunderstorms are frequently heavy but variable, as parts of the city may receive substantial rainfall while other sectors will have none. Strong wind gusts in the central business district are caused by the channeling of winds between tall buildings; the nickname "windy city," often applied to Chicago, does not, however, refer to the average wind speed, which is no greater than in many other parts of the country. Chicagoans instead attribute the nickname to their reputed penchant for talking proudly about their city.
Area: 228.4 square miles (2000)
Elevation: 578.5 feet above sea level
Average Temperatures: January, 21.3° F; July, 73.4° F; annual average, 49.8° F
Average Annual Precipitation: 35.82 inches