S
M
T
W
T
F
S
30
78°
55°
31
78°
53°
1
77°
52°
2
77°
51°
3
74°
49°
4
71°
52°
5
70°
45°
6
70°
51°
7
68°
51°
8
71°
50°
9
75°
52°
10
67°
47°
11
66°
51°
12
67°
50°
13
66°
51°
14
73°
51°
15
75°
45°
16
67°
44°
17
66°
48°
18
69°
45°
19
72°
44°
20
Hist. Avg.
65°
47°
21
Hist. Avg.
65°
47°
22
Hist. Avg.
64°
46°
23
Hist. Avg.
64°
46°
24
Hist. Avg.
64°
46°
25
Hist. Avg.
63°
46°
26
Hist. Avg.
63°
46°
27
Hist. Avg.
63°
46°
28
Hist. Avg.
62°
45°
29
Hist. Avg.
62°
45°
30
Hist. Avg.
61°
45°
1
Hist. Avg.
61°
45°
2
Hist. Avg.
61°
45°
3
Hist. Avg.
60°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Chemainus
Chemainus's September 2026 forecast shows daily high temperatures ranging from 66° to 78°, with overnight lows between 44° and 55°. The average high for September is 71° 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 Chemainus. See also: October | November | December.
