Portsmouth Water Temperature

Portsmouth is a town close to Gulf of Maine. August is the month with the warmest water temperature at 64.2°F / 17.9°C. The coolest month is March with an avg. water temperature of 37.8°F / 3.2°C. October is the sunniest at 0in / 0mm and January the wettest month with 1.1in / 28.2mm. The average air temperature is around 71.4°F / 21.9°C, July is the hottest month in a year. January is the coolest with 25.2°F / -3.8°C average air temperature. Warm-summer humid continental climate would be the climate here. June, July, August, September would be the best time to visit.

Portsmouth Summary

Description Value
Current water temperature 41 °F / 5 °C
Warmest Month Water Temperature: August with 64.2°F / 17.9°C
Coldest Month Water Temperature: March with 37.8°F / 3.2°C
Warmest Month Air Temperature: July with 71.4°F / 21.9°C
Coldest Month Air Temperature: January with 25.2°F / -3.8°C
Wettest Month: January with 1.1in / 28.2mm
Driest Month: October with 0in / 0mm
Highest Humidity August with 75.4%
Lowest Humidity February with 66.3%
Best Time to Visit: June, July, August, September
Climate Classification Warm-summer humid continental climate

Portsmouth water temperature by month

Gulf of Maine water temperature by month

Max. Water

Temperature (°F)

ø. Water

Temperature (°F)

Min. Water

Temperature (°F)

January

43.2 41.4 39.6

February

39.6 38.7 37.9

March

38.8 37.9 37.6

April

44.2 41.2 38.8

May

51.8 47.7 44.4

June

59.4 55.4 51.8

July

64.2 62.1 58.6

August

64.8 64 62.6

September

63.1 60.6 58.1

October

57.9 54.5 51.1

November

51.1 49.1 47.1

December

47.1 45.1 43.2

Gulf of Maine water temperature by month

Max. Water

Temperature (°C)

ø. Water

Temperature (°C)

Min. Water

Temperature (°C)

January

6.2 5.2 4.2

February

4.2 3.7 3.3

March

3.8 3.3 3.1

April

6.8 5.1 3.8

May

11 8.7 6.9

June

15.2 13 11

July

17.9 16.7 14.8

August

18.2 17.8 17

September

17.3 15.9 14.5

October

14.4 12.5 10.6

November

10.6 9.5 8.4

December

8.4 7.3 6.2
August is the month with the highest water temperature at 64.2°F / 17.9°C. The month with the lowest is March with an average water temperature of 37.8°F / 3.2°C.

Portsmouth weather today & 14-day weather forecast

Date
Weather
Max. F
Min. F
Max. C
Min. C
Windspeed
Windir.
Precip.
Rainrisk
Rel. Humidity
Mar. 05
Few clouds
45 °F
30°F
7 °C
-1°C
3mph (4km/h)
northwest
0in (0mm)
0 %
49%
Mar. 06
Scattered clouds
49 °F
33°F
9 °C
1°C
2mph (3km/h)
southwest
0in (0mm)
0 %
55%
Mar. 07
Few clouds
42 °F
33°F
5 °C
0°C
2mph (3km/h)
south-southwest
0in (0mm)
0 %
69%
Mar. 08
Clear Sky
50 °F
33°F
10 °C
0°C
2mph (3km/h)
west
0in (0mm)
0 %
39%
Mar. 09
Scattered clouds
64 °F
35°F
18 °C
2°C
2mph (3km/h)
southwest
0in (0mm)
0 %
51%
Mar. 10
Broken clouds
68 °F
45°F
20 °C
7°C
2mph (3km/h)
south-southwest
0in (0mm)
0 %
58%
Mar. 11
Few clouds
71 °F
47°F
22 °C
8°C
3mph (4km/h)
south-southwest
0in (0mm)
0 %
63%
Date
Weather
Max. F
Min. F
Max. C
Min. C
Windspeed
Windir.
Precip.
Rainrisk
Rel. Humidity
Mar. 12
Broken clouds
74 °F
51°F
23 °C
11°C
3mph (5km/h)
south-southwest
0in (0mm)
0 %
65%
Mar. 13
Overcast clouds
69 °F
55°F
21 °C
13°C
3mph (5km/h)
south-southwest
0in (0mm)
0 %
69%
Mar. 14
Broken clouds
59 °F
44°F
15 °C
7°C
4mph (6km/h)
southeast
0in (3mm)
45 %
80%
Mar. 15
Light shower rain
50 °F
44°F
10 °C
7°C
5mph (7km/h)
northeast
0in (3mm)
75 %
86%
Mar. 16
Light rain
64 °F
42°F
18 °C
6°C
5mph (7km/h)
south-southwest
0in (6mm)
85 %
76%
Mar. 17
Clear Sky
41 °F
36°F
5 °C
2°C
4mph (6km/h)
north-northwest
0in (0mm)
0 %
43%
Mar. 18
Scattered clouds
50 °F
36°F
10 °C
2°C
2mph (4km/h)
east
0in (0mm)
0 %
49%
Mar. 19
Overcast clouds
64 °F
44°F
18 °C
7°C
2mph (4km/h)
south-southwest
0in (0mm)
0 %
68%
Mar. 20
Broken clouds
42 °F
36°F
6 °C
2°C
4mph (6km/h)
south
0in (1mm)
40 %
51%

Portsmouth weather by month / climate table

Max.

Temperature

°F

ø.

Temperature

°F

Min.

Temperature

(°F)

Precip.

(in)

Rainy Days

(d)

Rel. Humidity

(%)

January

37.4 25.2 13.5 1.1 1 67.8%

February

37.8 27.1 15.6 0.8 0 66.3%

March

47.5 34 21.7 0.3 0 67.4%

April

58.8 45 32.7 0.6 4 66.6%

May

71.2 55 42.8 0.5 1 72.3%

June

78.4 64.4 53.4 0.6 1 75.2%

July

81.1 71.4 63.5 0.2 2 74.1%

August

79.9 70.3 61.5 0.2 0 75.4%

September

75.9 64.2 54.7 0.2 1 75.2%

October

64.4 52.3 40.6 0 0 73.1%

November

57 42.1 31.8 0 0 71.3%

December

43.7 32.5 23.4 0.2 0 69.5%

Max.

Temperature

°C

ø.

Temperature

°C

Min.

Temperature

(°C)

Precip.

(mm)

Rainy Days

(d)

Rel. Humidity

(%)

January

3 -3.8 -10.3 28.2 1 67.8%

February

3.2 -2.7 -9.1 20.5 0 66.3%

March

8.6 1.1 -5.7 6.5 0 67.4%

April

14.9 7.2 0.4 14.9 4 66.6%

May

21.8 12.8 6 11.9 1 72.3%

June

25.8 18 11.9 16.3 1 75.2%

July

27.3 21.9 17.5 4.7 2 74.1%

August

26.6 21.3 16.4 4.6 0 75.4%

September

24.4 17.9 12.6 5.7 1 75.2%

October

18 11.3 4.8 0 0 73.1%

November

13.9 5.6 -0.1 0 0 71.3%

December

6.5 0.3 -4.8 5.5 0 69.5%
October is the month with the lowest rain of 0in / 0mm and January with the highest precipitation in a year with 1.1in / 28.2mm. The avg. temperature is around 71.4°F / 21.9°C, July is the month with the highest temperature. January is the coolest with 25.2°F / -3.8°C average temperature.

Activities & POI in Portsmouth

Type of Activity List
Attraction Wentworth-Coolidge Historic Site