S
M
T
W
T
F
S
30
74°
47°
31
81°
42°
1
83°
46°
2
73°
53°
3
70°
40°
4
67°
45°
5
64°
43°
6
55°
41°
7
68°
52°
8
77°
43°
9
83°
42°
10
72°
58°
11
72°
50°
12
70°
47°
13
56°
47°
14
66°
46°
15
62°
42°
16
72°
44°
17
76°
50°
18
77°
48°
19
77°
47°
20
77°
49°
21
77°
48°
22
71°
44°
23
74°
49°
24
73°
51°
25
74°
49°
26
78°
51°
27
66°
42°
28
66°
41°
29
65°
42°
30
65°
40°
1
66°
37°
2
64°
39°
3
63°
36°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Ellensburg
Ellensburg's September 2026 forecast shows daily high temperatures ranging from 62° to 78°, with overnight lows between 36° and 51°. The average high for September is 70° with an average low of 45°. 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 Ellensburg. See also: October | November | December.
