S
M
T
W
T
F
S
30
81°
69°
31
91°
72°
1
94°
77°
2
93°
75°
3
94°
74°
4
95°
72°
5
86°
68°
6
85°
64°
7
79°
64°
8
85°
66°
9
85°
63°
10
79°
61°
11
74°
56°
12
78°
58°
13
74°
56°
14
74°
57°
15
75°
53°
16
78°
59°
17
77°
58°
18
70°
58°
19
75°
58°
20
75°
57°
21
74°
58°
22
74°
56°
23
70°
56°
24
72°
53°
25
75°
55°
26
75°
51°
27
65°
46°
28
63°
44°
29
64°
46°
30
63°
44°
1
62°
46°
2
66°
52°
3
64°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Willowbrook
Willowbrook's September 2026 forecast shows daily high temperatures ranging from 62° to 95°, with overnight lows between 44° and 75°. The average high for September is 76° with an average low of 57°. 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 Willowbrook. See also: October | November | December.
