Thunder Bay Weather in September

Thunder Bay in September sees pleasant daytime temperatures of 18°C (64°F) and nighttime lows of 10°C (50°F). With the highest rainfall of the year it is wise to pack an umbrella and expect frequent showers.

Rainfall in Thunder Bay in September

With this being the rainiest month, having an umbrella is essential to avoid unexpected rain. Looking at the last 30 years, the data shows about 13 days with rain, averaging 93 mm (3.7 in) for the month. Rainfall intensity is on the higher side this month. Expect more substantial showers rather than light, passing rain.

Temperature in Thunder Bay in September

Daytime highs in Thunder Bay in September reach 18°C (64°F), with nights around 10°C (50°F). September is part of summer. Conditions are often most pleasant around the middle of the day. At 10°C (50°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping.

Our weather planner can help you find worldwide destinations with pleasant weather during this period. July and August typically offer the best weather for Thunder Bay.

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• January
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For a detailed overview over the year and the best time to visit Canada, check out our Thunder Bay's climate page.

Thunder Bay Temperature in September

Min Temperature 10°C (50°F)  

Max Temperature 18°C (64°F)  

Chance of Rain 43%  

Precipitation 93 mm (3.7 in)  

Rainy days 13 days  

What to Wear in Thunder Bay in September

Comfortable temperatures call for an easy wardrobe in September. Pack summer basics like t-shirts and shorts, but include a light jacket for cooler moments. A pair of comfortable walking shoes is essential. Expect heavy rainfall, so bring good rain protection and waterproof bags.

What To Do in Thunder Bay in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Cycling

9/10

Walking

9/10

Camping

8/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit Canada, check out our Thunder Bay's climate page.

More climate data for Thunder Bay

Temperature Rainfall

See the full Thunder Bay climate overview or explore weather in Canada.