S
M
T
W
T
F
S
30
93°
68°
31
92°
68°
1
92°
67°
2
93°
68°
3
93°
61°
4
92°
60°
5
84°
60°
6
85°
66°
7
91°
64°
8
92°
67°
9
89°
67°
10
90°
68°
11
90°
66°
12
89°
65°
13
89°
62°
14
90°
63°
15
91°
66°
16
81°
63°
17
82°
65°
18
Hist. Avg.
84°
61°
19
Hist. Avg.
84°
60°
20
Hist. Avg.
84°
60°
21
Hist. Avg.
83°
60°
22
Hist. Avg.
83°
59°
23
Hist. Avg.
83°
59°
24
Hist. Avg.
82°
58°
25
Hist. Avg.
82°
58°
26
Hist. Avg.
82°
58°
27
Hist. Avg.
81°
57°
28
Hist. Avg.
81°
57°
29
Hist. Avg.
80°
56°
30
Hist. Avg.
80°
56°
1
Hist. Avg.
80°
55°
2
Hist. Avg.
79°
55°
3
Hist. Avg.
79°
54°
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 81° to 93°, with overnight lows between 60° and 68°. The average high for September is 89° with an average low of 65°. 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.
