S
M
T
W
T
F
S
30
79°
63°
31
73°
55°
1
70°
55°
2
69°
56°
3
68°
54°
4
69°
55°
5
73°
56°
6
64°
56°
7
72°
61°
8
82°
60°
9
84°
62°
10
86°
68°
11
79°
66°
12
79°
61°
13
75°
60°
14
78°
62°
15
70°
57°
16
67°
55°
17
67°
50°
18
71°
52°
19
74°
58°
20
71°
56°
21
66°
53°
22
72°
53°
23
79°
54°
24
78°
57°
25
74°
55°
26
78°
54°
27
77°
54°
28
74°
52°
29
69°
52°
30
69°
52°
1
68°
48°
2
66°
48°
3
67°
51°
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 66° to 79°, with overnight lows between 48° and 58°. The average high for September is 72° with an average low of 53°. 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.
