S
M
T
W
T
F
S
30
69°
43°
31
67°
42°
1
66°
39°
2
66°
34°
3
67°
34°
4
67°
35°
5
65°
34°
6
56°
32°
7
55°
35°
8
54°
41°
9
54°
41°
10
54°
38°
11
55°
32°
12
53°
36°
13
53°
37°
14
54°
34°
15
53°
33°
16
52°
32°
17
54°
33°
18
58°
39°
19
62°
33°
20
59°
35°
21
56°
29°
22
51°
29°
23
51°
32°
24
52°
32°
25
49°
30°
26
50°
31°
27
50°
33°
28
51°
34°
29
49°
33°
30
49°
31°
1
50°
34°
2
53°
38°
3
57°
35°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mt. Baker
Mt. Baker's September 2026 forecast shows daily high temperatures ranging from 49° to 69°, with overnight lows between 29° and 43°. The average high for September is 56° with an average low of 35°. 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 Mt. Baker. See also: October | November | December.
