Earliest and Latest Days of 25° C in London

This is a list of the earliest and latest days in the year with a high temperature of at least 25 °C in London, Ontario history. It is based on NOAA data from the years 1883–2024.

Also see:

Earliest 25 degree day in London?

The earliest in the year that London, Ontario had a high temperature of at least 25 °C is March 21 which happened in 2012.

Latest 25 degree day in London?

The latest in the year that London, Ontario had a high temperature of at least 25 °C is October 26 which happened in 1963.

Earliest Days ≥ 25 °C

Date	Year	Temperature
March 21	2012	25.7 °C
March 22	2012	27.2 °C
March 24	1910	26.1 °C
March 28	1910	25.0 °C
April 2	1963	25.6 °C
April 5	1921	25.0 °C
April 5	1910	26.1 °C
April 6	1929	27.2 °C
April 6	1921	26.7 °C
April 7	1991	26.1 °C
April 7	1929	26.7 °C
April 8	2021	26.0 °C
April 10	1922	26.1 °C
April 11	1977	25.6 °C
April 12	1977	26.8 °C
April 13	1977	25.9 °C
April 13	1941	28.9 °C
April 13	1931	25.6 °C
April 14	1883	26.7 °C
April 15	2010	25.2 °C
April 15	2003	27.2 °C
April 15	1976	25.6 °C

Latest Days ≥ 25 °C

Date	Year	Temperature
October 26	1963	25.6 °C
October 25	1963	25.6 °C
October 22	1947	25.6 °C
October 21	1947	25.0 °C
October 19	1953	26.7 °C
October 18	1963	26.7 °C
October 18	1950	25.0 °C
October 18	1910	26.1 °C
October 18	1908	26.7 °C
October 17	1963	26.1 °C
October 17	1956	25.0 °C
October 17	1938	27.2 °C
October 17	1908	25.6 °C
October 16	1963	26.1 °C
October 16	1962	25.0 °C
October 16	1938	27.2 °C
October 16	1897	26.1 °C
October 15	1920	26.1 °C
October 15	1908	27.8 °C
October 15	1897	29.4 °C