S
M
T
W
T
F
S
30
81°
59°
31
87°
57°
1
86°
58°
2
85°
53°
3
84°
55°
4
83°
56°
5
81°
68°
6
83°
70°
7
86°
69°
8
89°
68°
9
90°
68°
10
86°
63°
11
87°
63°
12
89°
67°
13
90°
67°
14
90°
68°
15
90°
67°
16
89°
67°
17
89°
65°
18
86°
60°
19
82°
60°
20
83°
61°
21
86°
63°
22
86°
63°
23
85°
61°
24
83°
57°
25
77°
55°
26
77°
55°
27
76°
54°
28
77°
55°
29
78°
56°
30
78°
56°
1
77°
55°
2
79°
60°
3
83°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Idyllwild
Idyllwild's September 2026 forecast shows daily high temperatures ranging from 76° to 90°, with overnight lows between 53° and 70°. The average high for September is 84° with an average low of 61°. 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 Idyllwild. See also: October | November | December.