S
M
T
W
T
F
S
27
64°
47°
28
63°
44°
29
63°
43°
30
64°
42°
1
66°
46°
2
67°
50°
3
66°
47°
4
66°
41°
5
61°
41°
6
60°
38°
7
59°
40°
8
58°
39°
9
59°
45°
10
60°
44°
11
58°
39°
12
57°
37°
13
56°
39°
14
57°
44°
15
Hist. Avg.
60°
41°
16
Hist. Avg.
60°
40°
17
Hist. Avg.
59°
40°
18
Hist. Avg.
59°
40°
19
Hist. Avg.
58°
39°
20
Hist. Avg.
58°
39°
21
Hist. Avg.
58°
39°
22
Hist. Avg.
57°
38°
23
Hist. Avg.
57°
38°
24
Hist. Avg.
57°
38°
25
Hist. Avg.
56°
38°
26
Hist. Avg.
56°
37°
27
Hist. Avg.
56°
37°
28
Hist. Avg.
55°
37°
29
Hist. Avg.
55°
36°
30
Hist. Avg.
54°
36°
31
Hist. Avg.
54°
36°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
October Weather in Portsmouth
Portsmouth's October 2026 forecast shows daily high temperatures ranging from 56° to 67°, with overnight lows between 37° and 50°. The average high for October is 61° with an average low of 43°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how October weather will actually feel in Portsmouth. See also: November | December | January.
