Climate

Chicago has four distinctive seasons. July is the hottest month in a year, with an average highest temperature of 29°C and an average lowest temperature of 17°C; January is the coldest month, with an average highest temperature of 2°C and an average lowest temperature of -11°C. The previous highest record was 40°C (July 24, 1934), and the lowest record was −32°C (January 20, 1985). Influenced by Michigan Lake, Chicago is windy in winter. Chicago features favorable temperature, and the average temperature is 6°C in January, 9°C in April, 22.8°C in July and 11.4°C in October. With abundant rainfall, the annual average rainfall is 965mm. Summer is a season with the most rainfall, and the rainfall often occurs in the form of thunderstorm and shower and continuous rainfall occurs rarely. In winter, Chicago has the least rainfall which generally occurs in the form of snow. The maximum daily rainfall was 164mm occurring on August 14, 1987.