Thunder Bay Climate: Weather by Month and Best Time to Visit
Best months for Thunder Bay: August, July.
Year at a glance
Weather by month
| Month | Avg high | Avg low | Rainfall | Rainy days | Humidity | Sunshine | Score |
|---|---|---|---|---|---|---|---|
| January | -9°C | -18°C | 29 mm | 6 | – | – | 4.2 |
| February | -7°C | -16°C | 22 mm | 5 | – | – | 4.4 |
| March | 0°C | -10°C | 31 mm | 7 | – | – | 4.2 |
| April | 6°C | -3°C | 54 mm | 8 | – | – | 5.1 |
| May | 14°C | 4°C | 66 mm | 10 | – | – | 6.4 |
| June | 19°C | 10°C | 65 mm | 10 | – | – | 7.3 |
| July | 23°C | 14°C | 76 mm | 11 | – | – | 7.7 |
| August | 22°C | 14°C | 67 mm | 9 | – | – | 7.9 |
| September | 17°C | 9°C | 84 mm | 10 | – | – | 7.0 |
| October | 9°C | 3°C | 73 mm | 11 | – | – | 5.6 |
| November | 2°C | -4°C | 49 mm | 8 | – | – | 4.3 |
| December | -5°C | -13°C | 38 mm | 8 | – | – | 4.1 |