The climate of Thunder Bay is influenced by Lake Superior, resulting in cooler summer temperatures and warmer winter temperatures. So when visiting, it’s important to pack for cooler weather and plan to wear layers that can easily accodate the temperature for that part of the day.

The average daily temperatures range from a high of 62 F/17.6 °C in July and a low of 5°F/-14.8 °C in January; the average daily high in July is 75°F/24.2 °C and the average daily high in January is 17°F/-8.6 °C. Summer daytime temperatures vary from 15° C to 30° C, while nights tend to be cooler and less humid than southern locations.

The summer period is well suited to both active and passive outdoor recreational pursuits. Recent winter daytime temperatures have ranged from springlike to relatively cold with sunny days. This type of climate is well suited to all kinds of active outdoor recreational pursuits. Spring and autumn are short with cool days and evenings.

Winter outdoor recreation often extends well into April while summer culminates in a spectacular show of colours in the fall.Precipitation is highly variable from year to year. The annual average rainfall is 527.3 mm while the average snowfall is 213 cm.
On average, Thunder Bay is the sunniest location in eastern, sunnier than any city in Canada located to the east of it.

Current Thunder Bay Weather

Observed at Thunder Bay Airport on 2012-02-03 23:00:00

	-3°C Mainly Clear
		Feels Like	-8	Wind	W 13 km/h
		Humidity	87 %	Pressure	103.0 kPa falling
		Dew Point	-5.2°C	Visibility	24.1 km
		Air Quality		Temperature	-3.3°C

Short Term Forecast

	Friday Night	Saturday	Saturday Night	Sunday	Monday
	Increasing Cloudiness	Mainly Cloudy	Partly Cloudy	Cloudy	Sunny
Low	-5°C		-14°C		-5°C
High		1°C		3°C	-3°C

Detailed Thunder Bay Weather Forecast

Friday Night	Increasing cloudiness near midnight. Low minus 5. Forecast issued 4:00 PM EST Friday 03 February 2012
Saturday	Cloudy. Becoming a mix of sun and cloud in the afternoon. High plus 1. Forecast issued 4:00 PM EST Friday 03 February 2012
Saturday Night	Partly cloudy. Low minus 14. Forecast issued 4:00 PM EST Friday 03 February 2012
Sunday	Cloudy. High plus 3. Forecast issued 4:00 PM EST Friday 03 February 2012
Monday	Sunny. Low minus 5. High minus 3. Forecast issued 4:00 PM EST Friday 03 February 2012
Tuesday	Sunny. Low minus 18. High minus 6. Forecast issued 4:00 PM EST Friday 03 February 2012
Wednesday	Sunny. Low minus 17. High minus 6. Forecast issued 4:00 PM EST Friday 03 February 2012
Thursday	Sunny. Low minus 13. High minus 5. Forecast issued 4:00 PM EST Friday 03 February 2012