S
M
T
W
T
F
S
30
84°
59°
31
83°
58°
1
87°
63°
2
89°
65°
3
88°
63°
4
89°
58°
5
90°
57°
6
87°
59°
7
88°
64°
8
89°
63°
9
90°
63°
10
88°
62°
11
87°
63°
12
86°
62°
13
86°
62°
14
87°
61°
15
89°
62°
16
87°
62°
17
81°
61°
18
80°
56°
19
79°
53°
20
78°
54°
21
77°
53°
22
78°
51°
23
76°
55°
24
76°
58°
25
80°
57°
26
84°
59°
27
75°
59°
28
83°
58°
29
79°
58°
30
74°
48°
1
76°
45°
2
72°
44°
3
70°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Swansea
Swansea's September 2026 forecast shows daily high temperatures ranging from 70° to 90°, with overnight lows between 44° and 65°. The average high for September is 83° with an average low of 58°. 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 Swansea. See also: October | November | December.
