S
M
T
W
T
F
S
30
88°
82°
31
87°
81°
1
88°
80°
2
86°
81°
3
87°
80°
4
87°
79°
5
88°
81°
6
87°
82°
7
87°
82°
8
86°
80°
9
86°
80°
10
87°
80°
11
87°
80°
12
88°
82°
13
88°
80°
14
89°
80°
15
90°
81°
16
89°
80°
17
90°
79°
18
89°
79°
19
90°
80°
20
90°
78°
21
89°
78°
22
89°
79°
23
88°
80°
24
88°
78°
25
89°
77°
26
88°
78°
27
88°
79°
28
87°
78°
29
89°
77°
30
88°
79°
1
88°
80°
2
89°
80°
3
89°
79°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Stock Island
Stock Island's September 2026 forecast shows daily high temperatures ranging from 86° to 90°, with overnight lows between 77° 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 Stock Island. See also: October | November | December.
