Measurements:
°C
°F
Thunder Bay
56°F
W 8 mph
Feels like: 54°F
Precip: 0%
World Resorts Canada Thunder Bay Weather May Weather in Thunder Bay

Thunder Bay Weather: May

Average Day Temperature: 53.4°F
Average Night Temperature: 41.1°F
Sea Water Temperature: 39.0°F
Number of Sunny Days: 12 days
Sunshine Hours: 14.6 - 15.8 hours
Number of Rainy Days: 1 day
Precipitation Totals: 0.6 in

Air Temperature in May, °F

Select Year: 2026 2025 2024

The highest day temperature in May 2026 was 90°F. The lowest night temperature was 23°F. The average values for day and night temperatures during May were 56.0°F и 37.0°F respectivly.

Thunder Bay Water Sea Temperature in May, °F

Select Year: 2026 2025 2024

The average sea surface temperature in May 2026 for Thunder Bay was 37.2°F. The maximum and minimum values were 32.2°F and 45.2°F respectively.

Sunny, Cloudy and Gloomy days

You can expect various weather conditions during May. Be ready for sunny, cloudy or even gloomy days.

Precipitation Totals in May, in

Precipitation total in May for Thunder Bay is 0.6 in.

Wind Speed in May, mph

The average wind speed in May is 7.0 mph.

Average Sunny Hours Per Day

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Thunder Bay in May is 8.6 hours.

Best Time to Visit Thunder Bay
The most sunny months:
September 14 days
August 14 days
July 12 days
The most warm months:
July 71.5 °F
August 71.2 °F
June 64.4 °F
Warmest sea temperature:
August 64.9 °F
September 61.3 °F
July 60.6 °F
The most cold months:
January 9.8 °F
February 11.1 °F
December 17.9 °F
The most rainy months:
September 2 days
August 2 days
April 2 days
The most windy months:
November 9 mph
December 9 mph
April 8 mph

Thunder Bay on the Weather Map

24 Hours Weather Forecast
Thunder Bay
Local time: 02:36
30 may, saturday
0300 56°F
W
8 mph
0600 52°F
W
8 mph
0900 54°F
W
9 mph
1200 56°F
W
11 mph
1500 54°F
W
11 mph
1800 52°F
W
9 mph
2100 44°F
W
3 mph
31 may, sunday
0000 40°F
W
2 mph