Weather in Portsmouth: August
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Average day temperature: | 77.0°F |
| Average night temperature: | 64.2°F | |
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Sea water temperature: | 65.0°F |
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Number of sunny days: | 11 days |
| Day length: | 13.2 - 14.5 hours | |
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Number of rainy days: | 2 days |
| Precipitation totals: | 1.1 in. | |
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forecast
| Portsmouth |
temperature
| Portsmouth |
Air temperature in August, °F
The highest day temperature during August of 2025 was 94°F. At the same time the lowest night temperature was 52°F. Daily and nightly averages during August were 79.1°F and 61.4°F.
Sea water temperature in Portsmouth in August, °F
The average sea water temperature in August of 2025 was 63.3°F. The highest and lowest sea temperatures during the month were 65.3°F and 59.7°F.
Number of sunny, partly cloudy and cloudy days in August is almost equal.
Precipitation total in August, in.
Precipitation total value in Portsmouth in August is 1.1 in. Other months of the year show relatively similar values.
The average wind speed value in August is 6.5 mph It makes August lest windy month 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 August is: 8.0.
Best time for vacation in Portsmouth
Portsmouth on a weather map
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