S
M
T
W
T
F
S
30
68°
63°
31
76°
65°
1
88°
70°
2
85°
67°
3
83°
65°
4
74°
64°
5
78°
59°
6
76°
56°
7
76°
55°
8
77°
54°
9
75°
65°
10
73°
59°
11
75°
55°
12
78°
63°
13
78°
54°
14
69°
59°
15
81°
62°
16
69°
61°
17
70°
60°
18
69°
54°
19
65°
54°
20
66°
53°
21
67°
54°
22
69°
55°
23
70°
58°
24
68°
51°
25
61°
54°
26
68°
57°
27
71°
56°
28
70°
54°
29
66°
55°
30
68°
56°
1
69°
54°
2
64°
55°
3
66°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in St. Thomas
St. Thomas's September 2026 forecast shows daily high temperatures ranging from 61° to 81°, with overnight lows between 51° and 63°. The average high for September is 69° with an average low of 56°. 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 St. Thomas. See also: October | November | December.
