S
M
T
W
T
F
S
30
87°
81°
31
86°
81°
1
87°
80°
2
87°
82°
3
88°
82°
4
87°
81°
5
87°
81°
6
88°
80°
7
87°
81°
8
87°
81°
9
88°
80°
10
87°
81°
11
87°
82°
12
88°
81°
13
88°
82°
14
88°
80°
15
88°
79°
16
89°
79°
17
88°
80°
18
90°
79°
19
89°
80°
20
89°
80°
21
88°
81°
22
90°
80°
23
90°
79°
24
89°
79°
25
89°
78°
26
88°
79°
27
90°
79°
28
90°
78°
29
89°
80°
30
89°
79°
1
90°
78°
2
89°
79°
3
88°
78°
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 86° to 90°, with overnight lows between 78° and 82°. The average high for September is 88° with an average low of 80°. 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.
