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