S
M
T
W
T
F
S
30
90°
74°
31
88°
73°
1
87°
76°
2
90°
75°
3
86°
74°
4
89°
73°
5
88°
74°
6
89°
74°
7
90°
75°
8
90°
74°
9
89°
75°
10
90°
75°
11
90°
74°
12
89°
75°
13
90°
75°
14
89°
74°
15
89°
73°
16
88°
73°
17
87°
72°
18
88°
71°
19
88°
72°
20
86°
73°
21
88°
72°
22
85°
73°
23
88°
71°
24
87°
72°
25
88°
68°
26
88°
71°
27
85°
70°
28
86°
70°
29
88°
70°
30
Hist. Avg.
85°
66°
1
Hist. Avg.
85°
66°
2
Hist. Avg.
85°
66°
3
Hist. Avg.
85°
65°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Sunnyside
Sunnyside's September 2026 forecast shows daily high temperatures ranging from 85° to 90°, with overnight lows between 68° and 76°. The average high for September is 88° with an average low of 73°. 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.
