S
M
T
W
T
F
S
30
76°
62°
31
79°
63°
1
81°
63°
2
81°
62°
3
80°
56°
4
80°
54°
5
73°
55°
6
74°
60°
7
75°
60°
8
79°
61°
9
77°
60°
10
78°
59°
11
77°
58°
12
78°
58°
13
77°
59°
14
77°
60°
15
78°
60°
16
78°
55°
17
77°
59°
18
74°
56°
19
76°
53°
20
72°
50°
21
69°
48°
22
68°
54°
23
68°
53°
24
74°
49°
25
67°
47°
26
66°
48°
27
67°
52°
28
72°
54°
29
71°
50°
30
72°
49°
1
64°
52°
2
65°
45°
3
69°
45°
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 81°, with overnight lows between 45° and 63°. The average high for September is 74° 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.
