Thunder Bay weather in August
Mild and comfortable, with some rainy days. Average highs of 21°C and lows of 15°C, with around 10 rainy days expected throughout the month.
While August isn't our top-rated month for Thunder Bay, it has its own appeal — typically lower prices, fewer crowds, and a more local feel.
Average high
21°C
Average low
15°C
Rainy days
10 days
Best months to visit
Year-round
What to do in Thunder Bay in August
Whatever the weather, Thunder Bay rewards curious visitors. Here are some of the best ways to spend your time:
Climb the Sleeping Giant overlooking the harbor
Kayak or paddleboard Lake Superior's calm bays
Fish for trout in nearby streams and lakes
Visit the Thunder Bay National Marine Conservation Area
Hike trails with dramatic lake and mountain views
Explore the historic waterfront and port infrastructure
What to pack for August
Light layers work well — T-shirts and shorts for the day, a light jacket for evenings. Comfortable walking shoes are a must. Bring a compact umbrella just in case.
Browse other months
January
-8C
Cold, with occasional showers.
February
-8C
Cold, with occasional showers.
March
-1C
Cold, with occasional showers.
April
5C
Cold, with some rainy days.
May
12C
Cool, with some rainy days.
June
18C
Mild and comfortable, with some rainy days.
July
22C
Mild and comfortable, with some rainy days.
August (you are here)
21C
Mild and comfortable, with some rainy days.
September
18C
Mild and comfortable, with some rainy days.
October
10C
Cool, with occasional showers.
November
3C
Cold, with occasional showers.
December
-3C
Cold, with occasional showers.
Book your August trip to Thunder Bay
Find hotels, tours and experiences for the perfect escape.
