Measurements:
°C
°F
CURRENT WEATHER
11:53
Portsmouth
20°F
SE 11 mph
Feels like: 10°F
Precip: 0%
World Resorts USA Portsmouth Weather

7 Day Weather Forecast

01.29
thu
DAY
20°F
SE 11 mph
precip
0%
NIGHT
4°F
E 15 mph
precip
0%
01.30
fri
DAY
8°F
E 13 mph
precip
0%
NIGHT
-2°F
SE 6 mph
precip
0%
01.31
sat
DAY
12°F
SE 4 mph
precip
0%
NIGHT
4°F
S 9 mph
precip
0%
02.01
sun
DAY
16°F
S 14 mph
precip
0%
NIGHT
10°F
SE 11 mph
precip
0%
02.02
mon
DAY
26°F
SE 9 mph
precip
0%
NIGHT
8°F
SE 5 mph
precip
0%
02.03
tue
DAY
26°F
SE 4 mph
precip
0%
NIGHT
16°F
E 6 mph
precip
0%
02.04
wed
DAY
26°F
E 12 mph
precip
45%
NIGHT
2°F
SE 11 mph
precip
0%

Portsmouth Sea Water Temperature in January, °F

Select Year: 2026 2025 2024

The average sea surface temperature in January 2026 for Portsmouth was 5.0°F. The maximum and minimum values were 4.1°F and 5.7°F respectively.

Portsmouth on the Weather Map

Best Time to Visit Portsmouth
The most sunny months:
November 16 days
October 14 days
September 13 days
The most warm months:
July 81.7 °F
August 80.0 °F
June 75.2 °F
Warmest sea temperature:
August 66.7 °F
July 64.8 °F
September 63.6 °F
The most cold months:
January 31.1 °F
February 32.4 °F
December 36.4 °F
The most rainy months:
July 3 days
April 3 days
August 2 days
The most windy months:
January 9 mph
March 9 mph
February 9 mph
more details