S
M
T
W
T
F
S
30
92°
71°
31
91°
70°
1
91°
70°
2
87°
69°
3
87°
69°
4
88°
68°
5
87°
67°
6
86°
68°
7
86°
68°
8
85°
67°
9
85°
63°
10
86°
67°
11
85°
63°
12
88°
66°
13
90°
67°
14
89°
60°
15
85°
60°
16
82°
61°
17
83°
60°
18
86°
61°
19
88°
60°
20
88°
62°
21
87°
64°
22
87°
64°
23
83°
63°
24
84°
59°
25
83°
59°
26
86°
58°
27
86°
58°
28
85°
61°
29
86°
61°
30
86°
62°
1
85°
61°
2
86°
62°
3
86°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Lake Arrowhead
Lake Arrowhead's September 2026 forecast shows daily high temperatures ranging from 82° to 92°, with overnight lows between 58° and 71°. The average high for September is 86° with an average low of 64°. 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 Lake Arrowhead. See also: October | November | December.
