S
M
T
W
T
F
S
30
79°
55°
31
78°
54°
1
78°
55°
2
79°
56°
3
77°
57°
4
76°
56°
5
79°
56°
6
78°
55°
7
77°
53°
8
76°
52°
9
75°
53°
10
76°
57°
11
75°
52°
12
75°
52°
13
77°
51°
14
78°
57°
15
77°
57°
16
78°
55°
17
74°
50°
18
74°
49°
19
75°
50°
20
77°
55°
21
73°
49°
22
72°
52°
23
75°
54°
24
76°
55°
25
77°
53°
26
76°
46°
27
74°
47°
28
68°
46°
29
67°
45°
30
67°
45°
1
Hist. Avg.
70°
46°
2
Hist. Avg.
70°
46°
3
Hist. Avg.
70°
45°
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 67° to 79°, with overnight lows between 45° and 57°. The average high for September is 75° with an average low of 52°. 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.
