| Month | Average (°C) | Record (°C) | Average (cm) | ||
|---|---|---|---|---|---|
| High ☀️ | Low 🌙 | High ☀️ | Low 🌙 | Precipitation 💧 | |
| January | -7.8 | -19.0 | 9.4 | -43.2 | 2.5 |
| February | -5.3 | -18.6 | 15.5 | -40.6 | 1.8 |
| March | 1.0 | -11.4 | 23.8 | -36.7 | 2.9 |
| April | 8.7 | -4.1 | 28.3 | -22.2 | 5.7 |
| May | 16.0 | 2.0 | 35.2 | -8.9 | 7.3 |
| June | 21.5 | 7.7 | 39.0 | -2.8 | 8.5 |
| July | 24.6 | 11.0 | 37.2 | 0.0 | 7.5 |
| August | 24.0 | 10.0 | 40.3 | -1.1 | 6.5 |
| September | 18.8 | 5.5 | 34.1 | -8.3 | 6.5 |
| October | 10.6 | -0.4 | 30.0 | -13.5 | 6.0 |
| November | 2.4 | -6.6 | 21.7 | -30.6 | 4.2 |
| December | -4.4 | -14.5 | 13.7 | -39.6 | 2.7 |
| Entire year | 9.4 | -3.1 | 40.3 | -43.2 | 61.0 |
|
More Thunder Bay Weather Records
1941–2024
|
||
|---|---|---|
| Highest daily low | 21.1 °C | August 24, 1947 |
| Lowest daily high | -29.5 °C | January 9, 1982 |
| Greatest daily range (Difference of high and low) |
33.7 °C | January 11, 1989 |
| Greatest difference in daily high over two conscutive days |
23.8 °C | May 30–31, 1986 |
| Most daily precipitation | 13.1 cm | September 8, 1977 |
| Most monthly precipitation | 28.4 cm | September 1977 |
| Most yearly precipitation | 104.6 cm | 1977 |
| Most yearly days with precipitation | 196 | 1999 |
| Earliest freeze | August 26 | 1950 |
| Earliest day ≥ 20 °C | March 20 | 2012 |
| Earliest day ≥ 25 °C | April 14 | 1958 |
| Earliest day ≥ 30 °C | May 4 | 1980 |
| Latest freeze | June 21 | 1992 |
| Latest day ≥ 20 °C | November 6 | 2020 |
| Latest day ≥ 25 °C | October 20 | 1978 |
| Latest day ≥ 30 °C | October 2 | 2023 |
| Most days in a year < 0 °C | 227 | 2002 |
| Most days in a year ≥ 20 °C | 109 | 2015 |
| Most days in a year ≥ 25 °C | 60 | 1955 |
| Most days in a year ≥ 30 °C | 19 | 1955 |
| Most days in a year ≥ 35 °C | 3 | 1988 |
| Most days in a year ≥ 40 °C | 1 | 1983 |
|
Thunder Bay Weather Streaks
Most consecutive days...
|
||
|---|---|---|
| With precipitation | 46 days | Aug 9 – Sep 23, 2009 |
| Without precipitation | 34 days | Mar 22 – Apr 24, 1984 |
| Freezing temperatures High temperature ≤ 0 °C |
74 days | Dec 22, 1977 – Mar 5, 1978 |
| High temperature ≥ 20 °C | 77 days | Jun 22 – Sep 6, 2012 |
| High temperature ≥ 25 °C | 14 days | Aug 15–28, 2013 |
| High temperature ≥ 30 °C | 5 days | Aug 12–16, 2015 |