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Canada weather

Weather in Thunder Bay for September 2027

Your guide to Thunder Bay weather in September - trends and predictions

    Temperatures

  • In general, the average temperature in Thunder Bay at the beginning of September is 20.9 °C. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 18.6 °C by the end of September.

    • Rain 🌧️

  • Thunder Bay experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 131.5 mm.

    • More

  • Is September a good time to visit Thunder Bay? check out the best time to travel to Thunder Bay page.

  • ✨ Is September a good time to visit Thunder Bay? – Ask the AI Weatherman

Average dry days
23
Dry days
Average rainy days
7
Rainy days
Average snowy days
0
Snow days
Average temperatures
19°/11°
Temperatures
Average wind speed
16 km/h
Avg max wind
Average humidity
78 %
Avg humidity

Thunder Bay Weather September

Move between months or click on a day
August
October
Sun.Mon.Tue.Wed.Thu.Fri.Sat.
1
Sunny
23°
2
Light rain
25°
3
Moderate rain
23°
4
Light rain
19°
5
Light rain
20°
6
Light rain
18°
7
Partly cloudy
18°
8
Heavy rain
20°
9
Light rain
18°
10
Light rain shower
19°
11
Patchy rain possible
19°
12
Light rain
17°
13
Sunny
18°
14
Light rain
17°
15
Patchy rain possible
19°
16
Patchy rain possible
20°
17
Light rain
20°
18
Light rain
16°
19
Overcast
16°
20
Patchy rain possible
17°
21
Mist
17°
22
Heavy rain
17°
23
Sunny
16°
24
Overcast
16°
25
Mist
20°
26
Partly cloudy
18°
27
Fog
19°
28
Mist
21°
29
Patchy rain possible
19°
30
Light rain shower
19°

Temperatures trend during September in Thunder Bay

See the weather trend as well as the moving average line

September weather in Thunder Bay day by day

Click on a date for more information
August October
Date Weather Temperatures Rain UV More
1 Sept. Sunny
Sunny
 23° /13° 0 mm 5
2 Sept. Light rain
Light rain
 25° /13° 3.2 mm 6
3 Sept. Moderate rain
Moderate rain
 23° /11° 12.6 mm 5
4 Sept. Light rain
Light rain
 19° /12° 6.7 mm 4
5 Sept. Light rain
Light rain
 20° /11° 3.1 mm 5
6 Sept. Light rain
Light rain
 18° /8° 8.3 mm 4
7 Sept. Partly cloudy
Partly cloudy
 18° /8° 0.4 mm 4
8 Sept. Heavy rain
Heavy rain
 20° /9° 30.9 mm 4
9 Sept. Light rain
Light rain
 18° /12° 7.6 mm 5
10 Sept. Light rain shower
Light rain shower
 19° /11° 0.8 mm 5
11 Sept. Patchy rain possible
Patchy rain possible
 19° /11° 1.5 mm 4
12 Sept. Light rain
Light rain
 17° /11° 4.6 mm 3
13 Sept. Sunny
Sunny
 18° /11° 0.1 mm 4
14 Sept. Light rain
Light rain
 17° /9° 2.7 mm 4
15 Sept. Patchy rain possible
Patchy rain possible
 19° /13° 1.4 mm 4
16 Sept. Patchy rain possible
Patchy rain possible
 20° /12° 1.9 mm 4
17 Sept. Light rain
Light rain
 20° /11° 3.2 mm 4
18 Sept. Light rain
Light rain
 16° /11° 3.9 mm 4
19 Sept. Overcast
Overcast
 16° /10° 0 mm 4
20 Sept. Patchy rain possible
Patchy rain possible
 17° /12° 1.4 mm 4
21 Sept. Mist
Mist
 17° /11° 0.9 mm 4
22 Sept. Heavy rain
Heavy rain
 17° /11° 33.2 mm 4
23 Sept. Sunny
Sunny
 16° /11° 0 mm 4
24 Sept. Overcast
Overcast
 16° /10° 0 mm 3
25 Sept. Mist
Mist
 20° /11° 0.1 mm 4
26 Sept. Partly cloudy
Partly cloudy
 18° /11° 0 mm 4
27 Sept. Fog
Fog
 19° /11° 0.1 mm 4
28 Sept. Mist
Mist
 21° /10° 0 mm 4
29 Sept. Patchy rain possible
Patchy rain possible
 19° /12° 2.1 mm 3.9
30 Sept. Light rain shower
Light rain shower
 19° /11° 0.9 mm 3.8
Next
Important Notice
Our weather forecast for Thunder Bay in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Thunder Bay forecast closer to your planned date for the most up-to-date weather information.
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Thunder Bay in September - FAQ

What are the expected maximum and minimum temperatures in Thunder Bay during September?
Enjoy moderate daytime temperatures of up to 19° and cooler nights around 11°. Ideal for a range of outdoor activities, from hiking to city tours.

How much rainfall should be expected in Thunder Bay during September?
Significant rainfall exceeding 131.5 mm is expected in Thunder Bay during September, occurring over more than 7 days. Preparing for wet conditions is recommended in your planning.

What are the typical wind conditions in Thunder Bay during September?
The average wind speed in Thunder Bay during September is 16 km/h, suggesting breezy to windy conditions, depending on your activities.

September rainfall patterns in Thunder Bay

Explore the daily rainfall trends and prepare for Thunder Bays September weather 💧
Typically, Thunder Bay has 7 rainy days in September with a total of 131.5 mm of rainfall.

UV exposure in Thunder Bay during September

Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Get accurate weather forecasts for Thunder Bay, located at latitude 48.382 and longitude -89.25. Stay updated with localized weather information tailored for Thunder Bay.

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