Kitchener has a humid continental climate of the warm summer subtype ; large seasonal differences are seen, usually warm and humid summers and cold to occasionally very cold winters. Winter-like conditions generally last from the mid-December until mid-March, while summer temperatures generally occur from mid-May to close to the end of September.
March 2012 went down in the history books for Kitchener – between 16 and 22 March, temperatures ranged from 21.4 °C (70.5 °F) to 27.0 °C (80.6 °F)—7 record highs in a row. 19 March high of 24 °C (75.2 °F) is one of the highest winter temperatures ever recorded, while 22 March high of 27 °C (80.6 °F) is the highest for March in this area.
Temperatures during the year can exceed 30 °C (86.0 °F) in the summer and drop below −20 °C (−4.0 °F) in the winter several times a year, but prolonged periods of extreme temperatures are rare. The frost-free period for Kitchener averages about 147 frost-free days a year, a much lower number than cities on the Great Lakes due its inland location and higher elevation. Snowfall averages 160 centimetres (63 in) per year; this is high, but not nearly as high as areas more directly affected by lake-effect snow.
The highest temperature ever recorded in Kitchener was 38.3 °C (101 °F) on August 6 and 7, 1918, and again on July 27, 1941. The coldest temperature ever recorded was −34.1 °C (−29.4 °F) on February 16, 2015.