S
M
T
W
T
F
S
30
83°
63°
31
82°
58°
1
83°
59°
2
81°
57°
3
80°
56°
4
80°
56°
5
81°
61°
6
81°
61°
7
82°
58°
8
81°
58°
9
81°
57°
10
82°
62°
11
83°
62°
12
85°
61°
13
84°
59°
14
81°
62°
15
85°
61°
16
85°
59°
17
84°
60°
18
85°
58°
19
82°
57°
20
81°
52°
21
83°
50°
22
76°
48°
23
75°
56°
24
79°
57°
25
Hist. Avg.
77°
52°
26
Hist. Avg.
77°
52°
27
Hist. Avg.
76°
51°
28
Hist. Avg.
76°
51°
29
Hist. Avg.
75°
50°
30
Hist. Avg.
75°
50°
1
Hist. Avg.
74°
49°
2
Hist. Avg.
74°
49°
3
Hist. Avg.
74°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Helena
Helena's September 2026 forecast shows daily high temperatures ranging from 75° to 85°, with overnight lows between 48° and 63°. The average high for September is 82° with an average low of 58°. 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 Helena. See also: October | November | December.
