S
M
T
W
T
F
S
30
70°
61°
31
66°
57°
1
68°
54°
2
68°
55°
3
72°
57°
4
79°
61°
5
68°
54°
6
72°
50°
7
82°
61°
8
79°
59°
9
63°
50°
10
63°
46°
11
68°
50°
12
70°
54°
13
N/A
14
75°
55°
15
81°
60°
16
68°
47°
17
67°
53°
18
66°
50°
19
68°
53°
20
69°
48°
21
67°
49°
22
69°
49°
23
68°
48°
24
68°
48°
25
69°
47°
26
64°
45°
27
67°
49°
28
68°
52°
29
67°
51°
30
66°
51°
1
64°
50°
2
66°
51°
3
66°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Sankt Sebastian
Sankt Sebastian's September 2026 forecast shows daily high temperatures ranging from 64° to 81°, with overnight lows between 45° and 60°. The average high for September is 68° with an average low of 50°. 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 Sankt Sebastian. See also: October | November | December.
