S
M
T
W
T
F
S
30
97°
64°
31
100°
64°
1
100°
68°
2
100°
72°
3
100°
72°
4
100°
72°
5
102°
73°
6
91°
62°
7
88°
59°
8
96°
72°
9
99°
70°
10
80°
61°
11
84°
64°
12
89°
65°
13
87°
60°
14
83°
58°
15
81°
57°
16
84°
61°
17
83°
58°
18
82°
58°
19
80°
54°
20
82°
59°
21
83°
59°
22
81°
58°
23
81°
58°
24
82°
57°
25
83°
59°
26
83°
59°
27
82°
58°
28
82°
59°
29
81°
59°
30
81°
57°
1
77°
52°
2
68°
46°
3
67°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sullivan
Sullivan's September 2026 forecast shows daily high temperatures ranging from 67° to 99°, with overnight lows between 44° and 72°. The average high for September is 83° with an average low of 59°. 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 Sullivan. See also: October | November | December.
