CanadaThe weather in September in Thunder Bay
It's pleasantly warm in September in Thunder Bay with an average temperature of 19°C. Temperatures this month range from a low of 14°C to a high of 23°C. At night, you can expect temperatures between 5°C and 11°C.
Looking for great weather? September is a good time to be in Thunder Bay. The temperatures are nice, and there’s not too much rain.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in September for Thunder Bay, Canada. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 32°C in 2023, Thunder Bay reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 6°C in 2018. The extreme nighttime temperatures ranged from a lowest recorded value of -3°C to a highest value of 19°C.
Rainfall amount
In September, there is an average of 81 mm of precipitation, spread over 11 days. The wind speed is around 4 Bft, mostly coming from the South.
Daily weather in September for Thunder Bay
Click on any day in September to get detailed info about the usual weather on that day in Thunder Bay. Check out the historical temperatures and precipitation over the past 10 years on this day.
September weather comparison
| Thunder Bay | New York | |
|---|---|---|
| Average temperature | 19°C | 27°C |
| Max. temperature | 23°C | 31°C |
| Min. temperature | 5°C | -5°C |
| Total precipitation | 81 mm | 57 mm |
| Rainy days | 11 days | 9 days |
Start of September
The month of September starts in Thunder Bay with mild temps, averaging around 21°C during the day and nights around 10°C.
Mid September
By mid-September, daytime temps drop to around 20°C, with nights around 10°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
End of September
By the end of September, the average daytime temperature in Thunder Bay is around 18°C, while nighttime temps are about 8°C. A shower might pop up, but overall, the weather will be dry and sunny.
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UV index
The UV index is a maximum of 5 this month. That's a moderate value on the intensity scale of 1 to 11. Unprotected skin can burn in about 30 minutes.
Check out the climate of Thunder Bay for all months and discover the best travel time
Curious about the weather in other parts of Canada? Check out the climate and weather for spots like Vancouver, Toronto, Niagara Falls, or explore other destinations in Canada.
Temperature charts
These charts show the average temperatures in September in Thunder Bay, Canada. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in September in Thunder Bay
Temperature in September in Thunder Bay over the years
Precipitation charts
These charts show the average amount of precipitation in September in Thunder Bay, Canada. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in September in Thunder Bay
Total precipitation in September in Thunder Bay over the years
Daily UV index in September in Thunder Bay
This chart shows the average daily UV index in September in Thunder Bay, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in September in Thunder Bay
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Average weather in Thunder Bay by month
Click on a month below to see detailed weather info for Thunder Bay. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.