Current Sea Water Temperature:
+46.4°F
| Maximum Sea Water Temperature in December: | 50.8°F |
| Minimum Sea Water Temperature in December: | 41.0°F |
| Average water temperature in December: | 45.4°F |
| detailed information | |
Sea Water Temperature for the Last 10 Days:
| December 05 | 46.4°F | November 30 | 47.4°F |
| December 04 | 46.6°F | November 29 | 47.8°F |
| December 03 | 47.0°F | November 28 | 48.0°F |
| December 02 | 47.0°F | November 27 | 48.4°F |
| December 01 | 47.6°F | November 26 | 48.4°F |
When is the Warmest Sea for Portsmouth?
According to our data for the last three years for Portsmouth the highest average sea water temperature was in August, July and September.
Average Water Temperature by Month, °F
Sea Water Temperature in August
The average sea surface temperature in August 2025 for Portsmouth was 64.8°F. The maximum and minimum values were 60.8°F and 67.0°F respectively.
Sea Water Temperature in July
The average sea surface temperature in July 2025 for Portsmouth was 64.5°F. The maximum and minimum values were 61.8°F and 69.8°F respectively.
Sea Water Temperature in September
The average sea surface temperature in September 2025 for Portsmouth was 62.4°F. The maximum and minimum values were 58.4°F and 64.8°F respectively.
USA Resorts:
NAME
F°
| Chicago |  |
-2 |
| Hawaii | |
+78 |
| Honolulu | |
+78 |
| Houston | |
+44 |
| Las Vegas |  |
+40 |
| Los Angeles | |
+52 |
| Maui | |
+72 |
| Miami | |
+72 |
| Miami Beach |  |
+80 |
| New York | |
+18 |
| San Diego | |
+54 |
| San Francisco | |
+46 |
| Sarasota | |
+62 |
| Tampa | |
+62 |
| Washington | |
+28 |
Countries:
NAME
POPULARITY
24 Hours Weather Forecast
Portsmouth
Local time: 03:05
05 dec, friday
| 0600 |  |
4°F | E 6 mph |
| 0900 |  |
8°F | E 6 mph |
| 1200 | |
16°F | NE 7 mph |
| 1500 | |
22°F | NE 10 mph |
| 1800 |  |
22°F | NE 6 mph |
| 2100 | |
18°F | NE 6 mph |
06 dec, saturday
| 0000 | |
16°F | NE 6 mph |
| 0300 | |
14°F | NE 5 mph |