Current sea water temperature:
+34.9°F
| Minimum sea water temperature in April: | 38.7°F |
| Maximum sea water temperature in April: | 32.5°F |
| Average sea water temperature in April: | 34.5°F |
| more information | |
14 days
forecast
forecast
| Thunder Bay |
monthly
weather
weather
| Thunder Bay |
Sea water temperature for the last 10 days:
| April 27 | 34.9°F | April 22 | 34.2°F |
| April 26 | 34.7°F | April 21 | 33.4°F |
| April 25 | 34.7°F | April 20 | 33.4°F |
| April 24 | 34.5°F | April 19 | 33.3°F |
| April 23 | 34.3°F | April 18 | 33.3°F |
Monthly sea water temperature, °F
When is the warmest sea in Thunder Bay?
Based on the data about daily sea water temperature for the last three years the warmest sea in Thunder Bay was noticed in August, September and July.
Monthly Sea Temperatures in Thunder Bay, °F
Sea water temperature in August, °F
Show year:
2025
2024
2023
The average sea water temperature in August of 2025 was 63.2°F. The highest and lowest sea temperatures during the month were 68.0°F and 59.9°F.
Sea water temperature in September, °F
Show year:
2025
2024
2023
The average sea water temperature in September of 2025 was 59.9°F. The highest and lowest sea temperatures during the month were 62.2°F and 57.4°F.
Sea water temperature in July, °F
Show year:
2025
2024
2023
The average sea water temperature in July of 2025 was 61.1°F. The highest and lowest sea temperatures during the month were 64.9°F and 55.2°F.
current
weather
weather
| Thunder Bay |
weather in
May
May
| Thunder Bay |
Best time for vacation in Thunder Bay
Thunder Bay on a weather map
Places in Canada:
Name
°F
24 Hours Forecast
Thunder Bay
Local time: 12:57
April 27, monday
1500
46°F
W
12 mph
12 mph
1800
41°F
W
12 mph
12 mph
2100
39°F
W
10 mph
10 mph
April 28, tuesday
0000
37°F
S
7 mph
7 mph
0300
39°F
S
11 mph
11 mph
0600
41°F
SE
19 mph
19 mph
0900
39°F
SE
21 mph
21 mph
1200
41°F
SE
19 mph
19 mph
