S
M
T
W
T
F
S
30
88°
67°
31
88°
68°
1
87°
70°
2
89°
70°
3
85°
69°
4
83°
69°
5
83°
66°
6
82°
63°
7
82°
62°
8
84°
63°
9
87°
68°
10
86°
68°
11
89°
60°
12
82°
66°
13
83°
60°
14
84°
59°
15
82°
60°
16
85°
61°
17
86°
63°
18
87°
65°
19
86°
59°
20
86°
58°
21
79°
58°
22
79°
59°
23
78°
63°
24
79°
63°
25
80°
62°
26
78°
62°
27
83°
61°
28
79°
58°
29
82°
59°
30
83°
60°
1
82°
60°
2
82°
59°
3
76°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sumter
Sumter's September 2026 forecast shows daily high temperatures ranging from 76° to 89°, with overnight lows between 53° and 70°. The average high for September is 83° with an average low of 63°. 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 Sumter. See also: October | November | December.
