Current sea water temperature:
+43.5°F
| Minimum sea water temperature in December: | 50.7°F |
| Maximum sea water temperature in December: | 41.9°F |
| Average sea water temperature in December: | 45.8°F |
| more information | |
14 days
forecast
forecast
| Portsmouth |
monthly
weather
weather
| Portsmouth |
Sea water temperature for the last 10 days:
| December 24 | 43.5°F | December 19 | 43.9°F |
| December 23 | 43.5°F | December 18 | 44.4°F |
| December 22 | 43.7°F | December 17 | 44.2°F |
| December 21 | 44.1°F | December 16 | 44.1°F |
| December 20 | 44.2°F | December 15 | 45.0°F |
Monthly sea water temperature, °F
When is the warmest sea in Portsmouth?
Based on the data about daily sea water temperature for the last three years the warmest sea in Portsmouth was noticed in August, July and September.
Monthly Sea Temperatures in Portsmouth, °F
Sea water temperature in August, °F
Show year:
2025
2024
2023
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.
Sea water temperature in July, °F
Show year:
2025
2024
2023
The average sea water temperature in July of 2025 was 63.1°F. The highest and lowest sea temperatures during the month were 67.8°F and 60.6°F.
Sea water temperature in September, °F
Show year:
2025
2024
2023
The average sea water temperature in September of 2025 was 61.1°F. The highest and lowest sea temperatures during the month were 63.3°F and 57.6°F.
current
weather
weather
| Portsmouth |
weather in
December
December
| Portsmouth |
Best time for vacation in Portsmouth
Portsmouth on a weather map
Places in USA:
Name
°F
24 Hours Forecast
Portsmouth
Local time: 16:12
December 24, wednesday
1800
30°F
SW
5 mph
5 mph
2100
27°F
SE
3 mph
3 mph
December 25, thursday
0000
25°F
E
4 mph
4 mph
0300
23°F
E
5 mph
5 mph
0600
23°F
NE
6 mph
6 mph
0900
25°F
NE
9 mph
9 mph
1200
28°F
E
10 mph
10 mph
1500
32°F
E
9 mph
9 mph
