S
M
T
W
T
F
S
30
60°
49°
31
76°
45°
1
84°
41°
2
75°
47°
3
65°
46°
4
63°
48°
5
72°
48°
6
69°
51°
7
54°
51°
8
58°
46°
9
72°
45°
10
73°
43°
11
66°
49°
12
68°
51°
13
59°
41°
14
54°
42°
15
59°
48°
16
70°
42°
17
72°
38°
18
74°
41°
19
75°
45°
20
73°
41°
21
75°
39°
22
74°
38°
23
74°
38°
24
76°
37°
25
72°
41°
26
59°
30°
27
60°
30°
28
65°
32°
29
67°
45°
30
67°
37°
1
65°
39°
2
68°
38°
3
64°
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 59° to 68°, with overnight lows between 30° and 45°. The average high for September is 64° with an average low of 36°. 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.
