Weather in Thunder Bay: May
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Average day temperature: | 52.7°F |
| Average night temperature: | 42.6°F | |
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Sea water temperature: | 40.3°F |
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Number of sunny days: | 11 days |
| Day length: | 14.6 - 15.8 hours | |
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Number of rainy days: | 1 day |
| Precipitation totals: | 0.6 in. | |
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forecast
| Thunder Bay |
temperature
| Thunder Bay |
Air temperature in May, °F
The highest day temperature during May of 2025 was 75°F. At the same time the lowest night temperature was 32°F. Daily and nightly averages during May were 55.2°F and 42.5°F.
Sea water temperature in Thunder Bay in May, °F
The average sea water temperature in May of 2025 was 41.0°F. The highest and lowest sea temperatures during the month were 49.6°F and 36.1°F.
Number of sunny, partly cloudy and cloudy days in May is almost equal.
Precipitation total in May, in.
Precipitation total value in Thunder Bay in May is 0.6 in. Other months of the year show relatively similar values.
The average wind speed value in May is 6.9 mph It makes May one of the least windy months of the year.
This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in May is: 8.2.
Best time for vacation in Thunder Bay
Thunder Bay on a weather map
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