S
M
T
W
T
F
S
30
75°
46°
31
77°
49°
1
78°
50°
2
79°
51°
3
79°
50°
4
78°
51°
5
78°
51°
6
77°
53°
7
77°
53°
8
76°
50°
9
71°
48°
10
68°
50°
11
70°
51°
12
69°
50°
13
68°
48°
14
66°
43°
15
67°
43°
16
74°
44°
17
69°
44°
18
Hist. Avg.
80°
45°
19
Hist. Avg.
80°
45°
20
Hist. Avg.
79°
44°
21
Hist. Avg.
79°
44°
22
Hist. Avg.
78°
44°
23
Hist. Avg.
78°
44°
24
Hist. Avg.
78°
43°
25
Hist. Avg.
77°
43°
26
Hist. Avg.
77°
43°
27
Hist. Avg.
76°
42°
28
Hist. Avg.
76°
42°
29
Hist. Avg.
76°
42°
30
Hist. Avg.
75°
41°
1
Hist. Avg.
75°
41°
2
Hist. Avg.
74°
41°
3
Hist. Avg.
74°
40°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Glenbrook
Glenbrook's September 2026 forecast shows daily high temperatures ranging from 66° to 79°, with overnight lows between 43° and 53°. The average high for September is 73° 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 Glenbrook. See also: October | November | December.
