S
M
T
W
T
F
S
30
85°
38°
31
79°
36°
1
69°
36°
2
70°
38°
3
76°
42°
4
81°
48°
5
81°
46°
6
79°
37°
7
71°
36°
8
67°
39°
9
65°
40°
10
68°
45°
11
68°
37°
12
67°
35°
13
66°
45°
14
75°
45°
15
74°
39°
16
66°
35°
17
64°
34°
18
65°
36°
19
73°
35°
20
64°
34°
21
64°
36°
22
68°
31°
23
61°
32°
24
60°
41°
25
64°
36°
26
65°
30°
27
61°
40°
28
60°
31°
29
60°
35°
30
61°
31°
1
57°
30°
2
57°
30°
3
59°
37°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Columbia Falls
Columbia Falls's September 2026 forecast shows daily high temperatures ranging from 57° to 85°, with overnight lows between 30° and 48°. The average high for September is 68° with an average low of 37°. 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 Columbia Falls. See also: October | November | December.
