S
M
T
W
T
F
S
30
72°
45°
31
79°
39°
1
77°
46°
2
68°
46°
3
66°
43°
4
70°
50°
5
72°
46°
6
75°
50°
7
64°
39°
8
70°
39°
9
76°
42°
10
79°
49°
11
72°
46°
12
72°
39°
13
54°
32°
14
58°
36°
15
65°
41°
16
69°
42°
17
71°
42°
18
73°
43°
19
71°
44°
20
71°
42°
21
67°
35°
22
59°
39°
23
59°
34°
24
62°
40°
25
65°
40°
26
65°
39°
27
63°
36°
28
58°
28°
29
54°
26°
30
54°
27°
1
56°
30°
2
57°
32°
3
63°
35°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Ketchum
Ketchum's September 2026 forecast shows daily high temperatures ranging from 54° to 79°, with overnight lows between 26° and 49°. The average high for September is 65° with an average low of 38°. 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 Ketchum. See also: October | November | December.
