Earliest and Latest Days of 25° C in Thunder Bay

This is a list of the earliest and latest days in the year with a high temperature of at least 25 °C in Thunder Bay, Ontario history. It is based on NOAA data from the years 1941–2024.

Also see:

Earliest 25 degree day in Thunder Bay?

The earliest in the year that Thunder Bay, Ontario had a high temperature of at least 25 °C is April 14 which happened in 1958.

Latest 25 degree day in Thunder Bay?

The latest in the year that Thunder Bay, Ontario had a high temperature of at least 25 °C is October 20 which happened in 1978.

Earliest Days ≥ 25 °C

Date	Year	Temperature
April 14	1958	26.7 °C
April 18	1952	25.6 °C
April 19	1952	25.6 °C
April 20	1987	27.4 °C
April 22	1980	26.6 °C
April 23	1998	25.3 °C
April 23	1982	25.7 °C
April 23	1942	25.6 °C
April 24	1982	25.0 °C
April 24	1942	28.3 °C
April 29	1998	25.0 °C
April 29	1985	25.4 °C
April 29	1965	28.3 °C
April 29	1949	28.3 °C
April 30	2001	25.0 °C
April 30	1999	25.2 °C
April 30	1998	27.8 °C
April 30	1955	25.6 °C
April 30	1949	25.0 °C
May 1	1980	25.0 °C

Latest Days ≥ 25 °C

Date	Year	Temperature
October 20	1978	25.8 °C
October 19	2021	25.1 °C
October 17	1944	25.6 °C
October 15	1964	25.6 °C
October 15	1962	26.7 °C
October 14	1964	26.7 °C
October 12	1995	26.1 °C
October 9	1955	25.6 °C
October 8	2011	26.6 °C
October 8	2010	25.9 °C
October 8	1943	28.3 °C
October 6	1943	26.1 °C
October 5	1961	26.7 °C
October 3	2023	28.6 °C
October 3	1956	25.6 °C
October 2	2023	30.0 °C
October 2	1953	27.2 °C
October 1	2001	25.0 °C
September 30	1968	26.1 °C
September 28	1989	25.7 °C