S
M
T
W
T
F
S
30
80°
52°
31
81°
56°
1
82°
55°
2
82°
55°
3
81°
49°
4
80°
50°
5
79°
56°
6
80°
53°
7
81°
53°
8
78°
46°
9
71°
50°
10
73°
44°
11
76°
45°
12
74°
46°
13
70°
46°
14
70°
44°
15
69°
42°
16
70°
45°
17
69°
48°
18
67°
44°
19
68°
45°
20
68°
48°
21
72°
45°
22
73°
43°
23
72°
45°
24
Hist. Avg.
71°
47°
25
Hist. Avg.
71°
47°
26
Hist. Avg.
71°
47°
27
Hist. Avg.
70°
47°
28
Hist. Avg.
70°
46°
29
Hist. Avg.
69°
46°
30
Hist. Avg.
69°
46°
1
Hist. Avg.
68°
46°
2
Hist. Avg.
68°
46°
3
Hist. Avg.
68°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Chehalis
Chehalis's September 2026 forecast shows daily high temperatures ranging from 67° to 82°, with overnight lows between 42° and 56°. The average high for September is 75° with an average low of 48°. 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 Chehalis. See also: October | November | December.
