S
M
T
W
T
F
S
30
80°
52°
31
76°
66°
1
77°
66°
2
73°
65°
3
83°
70°
4
84°
63°
5
79°
59°
6
72°
52°
7
79°
47°
8
80°
52°
9
79°
55°
10
86°
66°
11
77°
53°
12
76°
65°
13
74°
65°
14
76°
54°
15
70°
57°
16
73°
61°
17
79°
64°
18
77°
57°
19
73°
54°
20
71°
53°
21
72°
54°
22
71°
53°
23
69°
55°
24
70°
52°
25
71°
52°
26
65°
51°
27
66°
55°
28
72°
55°
29
72°
53°
30
65°
51°
1
64°
52°
2
66°
53°
3
71°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Southampton
Southampton's September 2026 forecast shows daily high temperatures ranging from 64° to 79°, with overnight lows between 51° and 65°. The average high for September is 71° with an average low of 55°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Southampton. See also: October | November | December.
