Current sea water temperature:
+40.5°F
| Minimum sea water temperature in January: | 45.9°F |
| Maximum sea water temperature in January: | 39.4°F |
| Average sea water temperature in January: | 41.7°F |
| more information | |
14 days
forecast
forecast
| Portsmouth |
monthly
weather
weather
| Portsmouth |
Sea water temperature for the last 10 days:
| January 13 | 40.5°F | January 8 | 41.7°F |
| January 12 | 40.8°F | January 7 | 41.7°F |
| January 11 | 41.0°F | January 6 | 41.5°F |
| January 10 | 41.0°F | January 5 | 41.7°F |
| January 9 | 40.8°F | January 4 | 41.9°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
January
January
| Portsmouth |
Best time for vacation in Portsmouth
Portsmouth on a weather map
Places in USA:
Name
°F
24 Hours Forecast
Portsmouth
Local time: 05:16
January 13, tuesday
0600
32°F
NE
9 mph
9 mph
0900
32°F
NE
9 mph
9 mph
1200
43°F
E
10 mph
10 mph
1500
46°F
NE
9 mph
9 mph
1800
39°F
N
7 mph
7 mph
2100
36°F
N
11 mph
11 mph
January 14, wednesday
0000
36°F
NE
12 mph
12 mph
0300
36°F
NE
11 mph
11 mph
