S
M
T
W
T
F
S
30
55°
52°
31
55°
50°
1
62°
42°
2
60°
42°
3
63°
41°
4
59°
47°
5
58°
54°
6
61°
54°
7
61°
53°
8
60°
47°
9
54°
48°
10
57°
48°
11
57°
46°
12
56°
48°
13
54°
51°
14
53°
46°
15
58°
49°
16
54°
49°
17
53°
46°
18
52°
45°
19
52°
45°
20
53°
44°
21
51°
42°
22
51°
42°
23
52°
44°
24
51°
43°
25
52°
42°
26
51°
42°
27
50°
43°
28
54°
47°
29
51°
46°
30
54°
46°
1
51°
47°
2
51°
47°
3
52°
46°
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 50° to 63°, with overnight lows between 41° and 54°. The average high for September is 55° with an average low of 46°. 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.
