S
M
T
W
T
F
S
30
77°
66°
31
86°
70°
1
88°
69°
2
87°
70°
3
87°
69°
4
87°
68°
5
87°
67°
6
84°
65°
7
80°
63°
8
75°
61°
9
77°
57°
10
76°
58°
11
73°
53°
12
74°
54°
13
73°
53°
14
76°
52°
15
80°
58°
16
80°
57°
17
79°
57°
18
80°
58°
19
80°
57°
20
79°
56°
21
79°
58°
22
80°
58°
23
80°
57°
24
79°
57°
25
79°
56°
26
78°
54°
27
79°
55°
28
78°
54°
29
77°
53°
30
77°
54°
1
76°
54°
2
76°
53°
3
75°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sumner
Sumner's September 2026 forecast shows daily high temperatures ranging from 73° to 88°, with overnight lows between 52° and 70°. The average high for September is 79° with an average low of 58°. 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 Sumner. See also: October | November | December.
