Earliest and Latest Days of 100° F in Janesville

This is a list of the earliest and latest days in the year with a high temperature of at least 100 °F in Janesville, Wisconsin history. It is based on NOAA data from the years 1893–2024.

Also see:

Earliest 100 degree day in Janesville?

The earliest in the year that Janesville, Wisconsin had a high temperature of at least 100 °F is June 19 which happened in 1953.

Latest 100 degree day in Janesville?

The latest in the year that Janesville, Wisconsin had a high temperature of at least 100 °F is September 2 which happened in 1953.

Earliest Days ≥ 100 °F

Date	Year	Temperature
June 19	1953	100 °F
June 20	1988	101 °F
June 21	1988	100 °F
June 25	1988	100 °F
July 1	1963	102 °F
July 5	2012	101 °F
July 6	2012	103 °F
July 7	2012	103 °F
July 10	1976	100 °F
July 10	1966	102 °F
July 14	1995	101 °F
July 15	1988	101 °F
July 17	1894	100 °F
July 22	1965	101 °F
July 26	1955	100 °F
July 27	1955	101 °F
August 1	1988	102 °F
August 3	1964	100 °F
August 16	1988	100 °F
August 17	1988	101 °F

Latest Days ≥ 100 °F

Date	Year	Temperature
September 2	1953	100 °F
September 1	1953	101 °F
August 31	1953	100 °F
August 24	1948	100 °F
August 24	1947	100 °F
August 19	1983	100 °F
August 17	1988	101 °F
August 16	1988	100 °F
August 3	1964	100 °F
August 1	1988	102 °F
July 27	1955	101 °F
July 26	1955	100 °F
July 22	1965	101 °F
July 17	1894	100 °F
July 15	1988	101 °F
July 14	1995	101 °F
July 10	1976	100 °F
July 10	1966	102 °F
July 7	2012	103 °F
July 6	2012	103 °F