Thunder Bay Intl climate by month
Averages and records for each calendar month at Thunder Bay Intl, Canada, from 2003 to 2026. The warmest month is July, averaging 25.2°C; the coolest is January at −7.2°C.
| Month | Avg high | Avg low | Record high | Record low | Years |
|---|---|---|---|---|---|
| January | −7.2°C | −18.3°C | 9.4°C27 January 2006 | −39.5°C22 January 2013 | 22 / 22 |
| February | −5.6°C | −18.5°C | 11.3°C18 February 2017 | −37.4°C15 February 2015 | 22 / 23 |
| March | 1.8°C | −10.5°C | 23.8°C31 March 2010 | −33.7°C5 March 2015 | 22 / 23 |
| April | 8.4°C | −3.8°C | 24.4°C29 April 2007 | −19.3°C5 April 2014 | 23 / 23 |
| May | 15.9°C | 2.2°C | 30.9°C25 May 2014 | −8.4°C11 May 2020 | 22 / 22 |
| June | 21.6°C | 8.0°C | 33.9°C20 June 2022 | −2.4°C3 June 2019 | 22 / 22 |
| July | 25.2°C | 11.4°C | 39.0°C13 July 2026 | 1.6°C8 July 2021 | 21 / 22 |
| August | 23.8°C | 10.4°C | 32.8°C17 August 2008 | 0.4°C18 August 2007 | 21 / 22 |
| September | 19.3°C | 6.2°C | 34.1°C11 September 2005 | −5.3°C30 September 2009 | 19 / 21 |
| October | 11.3°C | 0.7°C | 30.0°C2 October 2023 | −13.5°C30 October 2020 | 21 / 21 |
| November | 3.2°C | −6.2°C | 21.3°C3 November 2022 | −29.7°C30 November 2007 | 19 / 21 |
| December | −4.2°C | −14.0°C | 13.7°C14 December 2023 | −39.6°C31 December 2013 | 21 / 22 |
Years shows the number behind the average high, then the number holding a record for that month. They differ because a year contributes an average only when the month has at least 25 days of readings, while a single reading is enough to set a record. The average low is withheld on the same 25-day rule and is counted separately again; it is shown as a dash where the archive cannot support it. Across the twelve months here the averages rest on 19 to 23 years each.
See what Thunder Bay Intl is doing right now
Every figure on this page is computed from NOAA GHCN-Daily observations stored per station, per year, per month. Nothing is modelled, interpolated or estimated, and a month the archive never covered is left out rather than filled in. A station appears here only once all twelve months carry an average from at least 10 years. See how this is built.