S
M
T
W
T
F
S
30
88°
72°
31
93°
70°
1
96°
76°
2
99°
72°
3
99°
72°
4
97°
70°
5
100°
70°
6
93°
68°
7
88°
70°
8
90°
64°
9
91°
63°
10
93°
68°
11
95°
73°
12
91°
70°
13
93°
72°
14
96°
71°
15
88°
60°
16
87°
56°
17
87°
62°
18
90°
68°
19
90°
69°
20
91°
71°
21
90°
70°
22
86°
64°
23
88°
63°
24
80°
60°
25
82°
60°
26
83°
61°
27
81°
61°
28
83°
62°
29
82°
62°
30
82°
61°
1
79°
58°
2
79°
62°
3
83°
62°
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 79° to 96°, with overnight lows between 56° and 71°. The average high for September is 85° 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.
