S
M
T
W
T
F
S
30
92°
68°
31
92°
68°
1
91°
67°
2
91°
68°
3
92°
68°
4
92°
69°
5
91°
69°
6
91°
65°
7
88°
62°
8
85°
64°
9
86°
66°
10
89°
61°
11
89°
62°
12
88°
63°
13
85°
64°
14
88°
65°
15
89°
64°
16
88°
60°
17
84°
59°
18
82°
58°
19
80°
63°
20
81°
57°
21
81°
57°
22
79°
58°
23
79°
62°
24
80°
61°
25
82°
62°
26
85°
62°
27
84°
61°
28
85°
62°
29
84°
61°
30
79°
60°
1
78°
59°
2
82°
53°
3
77°
52°
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 77° to 92°, with overnight lows between 52° and 69°. The average high for September is 85° with an average low of 62°. 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.
