Current Sea Water Temperature:
+37.8°F
| Maximum Sea Water Temperature in May: | 53.6°F |
| Minimum Sea Water Temperature in May: | 32.2°F |
| Average water temperature in May: | 38.8°F |
| detailed information | |
Sea Water Temperature for the Last 10 Days:
| May 19 | 37.8°F | May 14 | 39.0°F |
| May 18 | 37.8°F | May 13 | 34.8°F |
| May 17 | 39.8°F | May 12 | 35.0°F |
| May 16 | 37.6°F | May 11 | 35.0°F |
| May 15 | 35.0°F | May 10 | 33.8°F |
When is the Warmest Sea for Thunder Bay?
According to our data for the last three years for Thunder Bay the highest average sea water temperature was in August, September and July.
Average Water Temperature by Month, °F
Sea Water Temperature in August
The average sea surface temperature in August 2025 for Thunder Bay was 64.6°F. The maximum and minimum values were 61.0°F and 70.0°F respectively.
Sea Water Temperature in September
The average sea surface temperature in September 2025 for Thunder Bay was 61.0°F. The maximum and minimum values were 58.2°F and 63.6°F respectively.
Sea Water Temperature in July
The average sea surface temperature in July 2025 for Thunder Bay was 62.4°F. The maximum and minimum values were 55.8°F and 66.6°F respectively.
Canada Resorts:
NAME
F°
| Bonavista | ![]() |
+38 |
| Halifax | ![]() |
+52 |
| Les Iles-de-la-Madeleine | ![]() |
+44 |
| Montreal | ![]() |
+74 |
| Ottawa | ![]() |
+74 |
| Prince Edward Island | ![]() |
+52 |
| Quebec | ![]() |
+52 |
| Saint John | ![]() |
+48 |
| Sydney | ![]() |
+42 |
| Thunder Bay | ![]() |
+40 |
| Tofino | ![]() |
+52 |
| Toronto | ![]() |
+72 |
| Vancouver | ![]() |
+52 |
| Victoria | ![]() |
+50 |
| Winnipeg | ![]() |
+38 |
Countries:
NAME
POPULARITY
24 Hours Weather Forecast
Thunder Bay
Local time: 07:52
19 may, tuesday
| 0900 | ![]() |
40°F | SE 8 mph |
| 1200 | ![]() |
38°F | SE 11 mph |
| 1500 | ![]() |
40°F | SE 12 mph |
| 1800 | ![]() |
42°F | SE 12 mph |
| 2100 | ![]() |
38°F | SE 11 mph |
20 may, wednesday
| 0000 | ![]() |
32°F | SE 7 mph |
| 0300 | ![]() |
30°F | SE 8 mph |
| 0600 | ![]() |
30°F | SE 9 mph |

































