S
M
T
W
T
F
S
30
81°
65°
31
82°
64°
1
85°
61°
2
84°
56°
3
76°
59°
4
77°
63°
5
76°
59°
6
84°
54°
7
77°
53°
8
75°
53°
9
74°
59°
10
75°
62°
11
76°
61°
12
81°
57°
13
81°
52°
14
73°
51°
15
70°
49°
16
71°
52°
17
71°
51°
18
72°
49°
19
75°
46°
20
69°
49°
21
69°
57°
22
71°
50°
23
78°
55°
24
76°
57°
25
76°
57°
26
75°
56°
27
77°
53°
28
76°
46°
29
72°
51°
30
63°
52°
1
70°
51°
2
72°
54°
3
72°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Stillwater
Stillwater's September 2026 forecast shows daily high temperatures ranging from 63° to 85°, with overnight lows between 46° and 65°. The average high for September is 75° with an average low of 55°. 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 Stillwater. See also: October | November | December.
