Climate averages 1991–2020
Thunder Bay weather
in January.
A freezing month with light precipitation: the coolest and the 2nd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
January is a freezing month in Thunder Bay: daytime highs average -9.6°C and nights cool to about -16.6°C. By daytime temperature it is the coolest month of the year.
Expect about 29 mm of precipitation on roughly 7 days, which makes January a month with light precipitation (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 8 h 49 min on an average January day.
The nearest other city in this atlas is Duluth (278 km away). In January its highs average -7.2°C, 2.4°C warmer than Thunder Bay, with 26 mm of precipitation.
Among the 86 cities listed in Canada, Thunder Bay ranks 83rd of 86 for the warmest January highs and 11th of 86 for the driest January (precipitation, lowest first). The mean January high of those 86 cities is -2.3°C; Thunder Bay is 7.3°C cooler than that mean.
From January to February, average highs rise by 1.7°C to -8.0°C, and monthly precipitation falls from 29 mm to 22 mm.
The annual picture
January in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Thunder Bay climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January, selected | -9.6°C-16.6°C | -16.6°C | 29 | 6.5 | 8.89 h |
| February | -8.0°C-15.0°C | -15.0°C | 22 | 4.9 | 10.210 h |
| March | -1.7°C-8.7°C | -8.7°C | 31 | 6.8 | 11.912 h |
| April | 5.1°C-2.2°C | -2.2°C | 54 | 8.3 | 13.614 h |
| May | 12.5°C4.2°C | 4.2°C | 66 | 10.1 | 15.215 h |
| June | 18.3°C10.7°C | 10.7°C | 65 | 10.5 | 16.016 h |
| July | 22.3°C15.3°C | 15.3°C | 76 | 10.6 | 15.716 h |
| August | 22.3°C15.6°C | 15.6°C | 67 | 9.1 | 14.314 h |
| September | 17.8°C11.7°C | 11.7°C | 84 | 10.5 | 12.613 h |
| October | 9.9°C4.8°C | 4.8°C | 72 | 10.4 | 10.911 h |
| November | 2.3°C-2.8°C | -2.8°C | 49 | 7.8 | 9.39 h |
| December | -4.8°C-11.3°C | -11.3°C | 38 | 7.4 | 8.48 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
January in nearby cities
- Duluth in JanuaryUnited States · 278 kmHigh -7.2°C · Low -13.9°C · 26 mm precipitation
- Sault Ste. Marie in JanuaryCanada · 424 kmHigh -6.5°C · Low -13.1°C · 46 mm precipitation
- Green Bay in JanuaryUnited States · 440 kmHigh -4.1°C · Low -11.9°C · 37 mm precipitation
- Appleton in JanuaryUnited States · 463 kmHigh -4.5°C · Low -12.3°C · 37 mm precipitation
- Brooklyn Park in JanuaryUnited States · 481 kmHigh -5.4°C · Low -13.9°C · 24 mm precipitation
- Saint Paul in JanuaryUnited States · 482 kmHigh -5.1°C · Low -13.5°C · 25 mm precipitation
- Minneapolis in JanuaryUnited States · 487 kmHigh -5.3°C · Low -13.7°C · 24 mm precipitation
- Plymouth, United States in JanuaryUnited States · 493 kmHigh -5.5°C · Low -13.6°C · 24 mm precipitation
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Thunder Bay) is explained once on the Thunder Bay year overview and on the Sources, method and limits page.