S
M
T
W
T
F
S
30
90°
77°
31
90°
82°
1
90°
80°
2
90°
83°
3
91°
83°
4
91°
80°
5
90°
78°
6
91°
82°
7
89°
82°
8
91°
80°
9
90°
82°
10
89°
81°
11
90°
84°
12
94°
78°
13
89°
78°
14
90°
79°
15
90°
80°
16
90°
80°
17
88°
78°
18
87°
80°
19
87°
79°
20
87°
80°
21
87°
81°
22
88°
82°
23
86°
80°
24
86°
80°
25
87°
81°
26
89°
80°
27
87°
81°
28
89°
80°
29
89°
80°
30
88°
81°
1
86°
82°
2
87°
81°
3
88°
81°
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 89°, with overnight lows between 79° and 82°. The average high for September is 87° with an average low of 81°. 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.
