S
M
T
W
T
F
S
30
74°
48°
31
86°
51°
1
66°
57°
2
66°
56°
3
62°
49°
4
72°
47°
5
75°
50°
6
75°
53°
7
74°
54°
8
80°
51°
9
86°
51°
10
72°
54°
11
69°
50°
12
64°
51°
13
62°
53°
14
69°
55°
15
69°
52°
16
81°
49°
17
84°
49°
18
72°
53°
19
71°
52°
20
73°
50°
21
72°
55°
22
73°
51°
23
67°
48°
24
71°
56°
25
61°
46°
26
68°
44°
27
68°
46°
28
69°
50°
29
64°
51°
30
67°
51°
1
70°
47°
2
65°
45°
3
68°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Rainier
Rainier's September 2026 forecast shows daily high temperatures ranging from 61° to 71°, with overnight lows between 44° and 56°. The average high for September is 67° 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 Rainier. See also: October | November | December.
