Earliest and Latest Days of 100° F in Philadelphia

This is a list of the earliest and latest days in the year with a high temperature of at least 100 °F in Philadelphia, Pennsylvania history. It is based on NOAA data from the years 1894–2024.

Also see:

Earliest 100 degree day in Philadelphia?

The earliest in the year that Philadelphia, Pennsylvania had a high temperature of at least 100 °F is June 5 which happened in 1925.

Latest 100 degree day in Philadelphia?

The latest in the year that Philadelphia, Pennsylvania had a high temperature of at least 100 °F is September 3 which happened in 1953.

Earliest Days ≥ 100 °F

Date	Year	Temperature
June 5	1925	100 °F
June 9	1933	100 °F
June 15	1994	100 °F
June 16	1991	100 °F
June 16	1957	100 °F
June 19	1994	100 °F
June 21	1923	100 °F
June 22	1988	100 °F
June 24	1923	100 °F
June 26	1952	100 °F
June 29	1934	101 °F
June 30	1964	100 °F
July 2	1966	100 °F
July 3	1966	104 °F
July 4	1966	103 °F
July 5	1999	100 °F
July 6	2010	102 °F
July 7	2012	101 °F
July 7	2010	103 °F
July 8	1993	100 °F

Latest Days ≥ 100 °F

Date	Year	Temperature
September 3	1953	100 °F
September 2	1953	100 °F
August 31	1953	101 °F
August 30	1953	100 °F
August 26	1948	100 °F
August 9	2001	101 °F
August 8	2001	100 °F
August 6	1955	100 °F
August 1	1933	100 °F
August 1	1917	101 °F
July 31	1954	102 °F
July 28	1941	100 °F
July 23	2011	101 °F
July 22	2011	103 °F
July 22	1957	100 °F
July 22	1955	100 °F
July 22	1926	100 °F
July 21	1977	100 °F
July 21	1957	101 °F
July 21	1930	102 °F