Weather in Portsmouth: January
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Average day temperature: | 33.2°F |
| Average night temperature: | 26.7°F | |
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Sea water temperature: | 41.7°F |
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Number of sunny days: | 10 days |
| Day length: | 9.1 - 9.9 hours | |
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Number of days with precipitation: | 3 days |
| Precipitation totals: | 1.2 in. | |
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| Portsmouth |
temperature
| Portsmouth |
Air temperature in January, °F
| Day temperature | Night temperature |
The highest day temperature during January of 2025 was 41°F. At the same time the lowest night temperature was 8°F. Daily and nightly averages during January were 30.2°F and 22.2°F.
Sea water temperature in Portsmouth in January, °F
The average sea water temperature in January of 2025 was 41.0°F. The highest and lowest sea temperatures during the month were 42.8°F and 39.4°F.
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| Partly cloudy days | |
| Cloudy days |
Mostly all days in January are cloudy but sunny and partly cloudy days are also possible.
Precipitation total in January, in.
Precipitation total value in Portsmouth in January is 1.2 in. Other months of the year show relatively similar values.
The average wind speed value in January is 9.7 mph It makes January one of the most 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 January is: 4.7.
Best time for vacation in Portsmouth
Portsmouth on a weather map
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