S
M
T
W
T
F
S
30
71°
48°
31
75°
39°
1
71°
51°
2
73°
45°
3
73°
43°
4
77°
43°
5
79°
52°
6
79°
45°
7
66°
45°
8
73°
36°
9
73°
36°
10
75°
37°
11
75°
46°
12
79°
43°
13
77°
50°
14
64°
37°
15
73°
34°
16
68°
50°
17
68°
52°
18
59°
46°
19
61°
41°
20
63°
36°
21
66°
36°
22
64°
45°
23
64°
41°
24
68°
39°
25
72°
43°
26
70°
39°
27
70°
41°
28
55°
43°
29
65°
39°
30
71°
41°
1
70°
40°
2
73°
43°
3
72°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Frontier
Frontier's September 2026 forecast shows daily high temperatures ranging from 65° to 73°, with overnight lows between 39° and 43°. The average high for September is 70° with an average low of 41°. 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 Frontier. See also: October | November | December.
