Weather in San Juan: December
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Average day temperature: | 82.0°F |
| Average night temperature: | 75.5°F | |
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Sea water temperature: | 82.2°F |
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Number of sunny days: | 6 days |
| Day length: | 11.0 - 11.1 hours | |
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Number of rainy days: | 3 days |
| Precipitation totals: | 1.6 in. | |
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forecast
| San Juan |
temperature
| San Juan |
Air temperature in December, °F
The highest day temperature during December of 2025 was 85°F. At the same time the lowest night temperature was 73°F. Daily and nightly averages during December were 81.8°F and 77.1°F.
Sea water temperature in San Juan in December, °F
The average sea water temperature in December of 2025 was 82.7°F. The highest and lowest sea temperatures during the month were 83.7°F and 81.5°F.
Mostly all days in December are partly cloudy but sunny or cloudy days are also possible.
Precipitation total in December, in.
Precipitation total value in San Juan in December is 1.4 in. Other months of the year show relatively similar values.
The average wind speed value in December is 10.4 mph It makes December 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 December is: 5.9.
Best time for vacation in San Juan
San Juan on a weather map
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