S
M
T
W
T
F
S
30
66°
48°
31
68°
55°
1
72°
56°
2
76°
52°
3
77°
55°
4
74°
48°
5
67°
48°
6
68°
53°
7
68°
52°
8
66°
49°
9
67°
52°
10
65°
54°
11
66°
53°
12
65°
49°
13
65°
51°
14
67°
53°
15
73°
53°
16
73°
46°
17
68°
46°
18
67°
45°
19
73°
49°
20
72°
53°
21
69°
47°
22
65°
46°
23
64°
46°
24
64°
44°
25
65°
44°
26
65°
43°
27
64°
51°
28
63°
51°
29
64°
48°
30
64°
49°
1
70°
51°
2
66°
49°
3
67°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Montesano
Montesano's September 2026 forecast shows daily high temperatures ranging from 63° to 77°, with overnight lows between 43° and 56°. The average high for September is 68° with an average low of 50°. 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 Montesano. See also: October | November | December.
