S
M
T
W
T
F
S
30
70°
49°
31
72°
56°
1
68°
52°
2
62°
50°
3
68°
51°
4
67°
50°
5
69°
51°
6
77°
50°
7
76°
51°
8
76°
52°
9
73°
48°
10
68°
44°
11
67°
44°
12
68°
51°
13
67°
45°
14
67°
43°
15
73°
47°
16
71°
46°
17
67°
46°
18
65°
45°
19
65°
43°
20
66°
42°
21
66°
41°
22
67°
42°
23
72°
45°
24
73°
44°
25
66°
47°
26
64°
43°
27
63°
43°
28
62°
41°
29
63°
41°
30
63°
44°
1
62°
43°
2
62°
42°
3
61°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Cathlamet
Cathlamet's September 2026 forecast shows daily high temperatures ranging from 61° to 77°, with overnight lows between 41° and 56°. The average high for September is 68° with an average low of 46°. 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 Cathlamet. See also: October | November | December.
