Weather in Grand Isle: December
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Average day temperature: | 62.5°F |
| Average night temperature: | 60.4°F | |
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Sea water temperature: | 65.9°F |
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Number of sunny days: | 10 days |
| Day length: | 10.3 - 10.4 hours | |
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Number of rainy days: | 2 days |
| Precipitation totals: | 0.9 in. | |
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forecast
| Grand Isle |
temperature
| Grand Isle |
Air temperature in December, °F
The highest day temperature during December of 2025 was 68°F. At the same time the lowest night temperature was 44°F. Daily and nightly averages during December were 60.2°F and 59.9°F.
Sea water temperature in Grand Isle in December, °F
The average sea water temperature in December of 2025 was 65.5°F. The highest and lowest sea temperatures during the month were 70.5°F and 61.3°F.
Number of sunny, partly cloudy and cloudy days in December is almost equal.
Precipitation total in December, in.
Precipitation total value in Grand Isle in December is 0.9 in. Other months of the year show relatively similar values.
The average wind speed value in December is 11.8 mph
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 December is: 5.6.
Best time for vacation in Grand Isle
Grand Isle on a weather map
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