S
M
T
W
T
F
S
30
93°
72°
31
96°
73°
1
97°
73°
2
99°
74°
3
100°
76°
4
102°
76°
5
102°
76°
6
97°
74°
7
97°
76°
8
92°
70°
9
93°
71°
10
93°
71°
11
91°
72°
12
89°
70°
13
89°
72°
14
91°
73°
15
90°
72°
16
89°
68°
17
87°
68°
18
86°
65°
19
84°
64°
20
85°
64°
21
84°
63°
22
88°
67°
23
87°
67°
24
87°
66°
25
86°
67°
26
87°
67°
27
87°
66°
28
86°
67°
29
85°
67°
30
86°
66°
1
86°
65°
2
82°
60°
3
74°
58°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Mountain Brook
Mountain Brook's September 2026 forecast shows daily high temperatures ranging from 74° to 93°, with overnight lows between 58° and 73°. The average high for September is 87° with an average low of 67°. 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 Mountain Brook. See also: October | November | December.
