Highest Daily Low Temperatures in Thunder Bay History

This is a list of the hottest daily low temperatures ever recorded in Thunder Bay, Ontario history from 1941–2024 based on data from the NOAA.

Highest temperatures all-time

Record for the highest daily low temperature in Thunder Bay

The highest low temperature for a calendar day in Thunder Bay, Ontario history was 21.1 °C which happened on Sunday, August 24, 1947.

Rank	Temperature	Date
1	21.1 °C	August 24, 1947
2	20.4 °C	August 25, 2013
3	20.1 °C	August 6, 2001
3	20.1 °C	August 3, 1989
5	20.0 °C	October 8, 2011
5	20.0 °C	July 22, 1955
5	20.0 °C	August 12, 1947
5	20.0 °C	August 20, 1945
9	19.8 °C	July 3, 2021
9	19.8 °C	August 11, 2010
9	19.8 °C	July 17, 2005
9	19.8 °C	June 6, 1988
13	19.4 °C	July 21, 2016
13	19.4 °C	July 29, 2015
13	19.4 °C	August 28, 1953
16	19.3 °C	August 13, 2010
16	19.3 °C	August 1, 2006
18	19.2 °C	August 31, 2010
18	19.2 °C	July 17, 2002
18	19.2 °C	July 23, 1987