S
M
T
W
T
F
S
30
89°
74°
31
88°
73°
1
87°
73°
2
89°
74°
3
89°
76°
4
90°
77°
5
91°
75°
6
90°
73°
7
88°
75°
8
88°
75°
9
86°
74°
10
87°
74°
11
86°
73°
12
88°
74°
13
89°
74°
14
88°
73°
15
88°
73°
16
87°
72°
17
88°
73°
18
88°
73°
19
87°
72°
20
88°
72°
21
88°
71°
22
87°
72°
23
88°
72°
24
88°
71°
25
87°
70°
26
87°
70°
27
86°
69°
28
86°
70°
29
84°
69°
30
85°
69°
1
86°
67°
2
86°
68°
3
Hist. Avg.
85°
65°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sunnyside
Sunnyside's September 2026 forecast shows daily high temperatures ranging from 84° to 91°, with overnight lows between 67° and 77°. The average high for September is 88° with an average low of 72°. 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 Sunnyside. See also: October | November | December.
