Current Sea Water Temperature:
+56.0°F
| Maximum Sea Water Temperature in June: | 66.2°F |
| Minimum Sea Water Temperature in June: | 50.0°F |
| Average water temperature in June: | 58.1°F |
| detailed information | |
Sea Water Temperature for the Last 10 Days:
| June 04 | 56.0°F | May 29 | 54.0°F |
| June 03 | 53.8°F | May 28 | 53.2°F |
| June 01 | 51.8°F | May 27 | 52.2°F |
| May 31 | 52.0°F | May 26 | 53.2°F |
| May 30 | 54.8°F | May 25 | 52.0°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°
| Boston |  |
+90 |
| Chicago | |
+76 |
| Hawaii |  |
+78 |
| Honolulu | |
+78 |
| Houston |  |
+86 |
| Las Vegas | |
+92 |
| Los Angeles |  |
+70 |
| Maui | |
+70 |
| Miami | |
+82 |
| Miami Beach | |
+84 |
| New York | |
+94 |
| San Diego | |
+64 |
| San Francisco | |
+60 |
| Sarasota | |
+94 |
| Tampa | |
+92 |
Countries:
NAME
POPULARITY
24 Hours Weather Forecast
Portsmouth
Local time: 12:54
04 jun, thursday
| 1500 |  |
90°F | N 6 mph |
| 1800 | |
84°F | NE 3 mph |
| 2100 |  |
74°F | E 5 mph |
05 jun, friday
| 0000 | |
66°F | E 6 mph |
| 0300 | |
62°F | E 6 mph |
| 0600 | |
62°F | SE 4 mph |
| 0900 |  |
74°F | SE 5 mph |
| 1200 | |
82°F | E 4 mph |