S
M
T
W
T
F
S
30
66°
49°
31
70°
53°
1
74°
57°
2
76°
56°
3
75°
55°
4
67°
47°
5
68°
47°
6
67°
49°
7
70°
49°
8
71°
54°
9
68°
48°
10
69°
47°
11
68°
49°
12
68°
55°
13
69°
47°
14
66°
45°
15
66°
47°
16
67°
48°
17
67°
49°
18
70°
49°
19
74°
52°
20
74°
46°
21
67°
48°
22
67°
47°
23
64°
46°
24
65°
45°
25
63°
42°
26
65°
43°
27
65°
47°
28
64°
51°
29
70°
50°
30
62°
44°
1
62°
47°
2
Hist. Avg.
65°
48°
3
Hist. Avg.
65°
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 62° to 76°, with overnight lows between 42° and 57°. The average high for September is 68° with an average low of 49°. 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.
