S
M
T
W
T
F
S
30
81°
69°
31
91°
72°
1
94°
77°
2
94°
75°
3
91°
73°
4
91°
73°
5
84°
68°
6
82°
68°
7
82°
65°
8
81°
67°
9
83°
70°
10
79°
64°
11
78°
66°
12
78°
63°
13
77°
63°
14
78°
62°
15
77°
60°
16
81°
65°
17
80°
64°
18
73°
64°
19
77°
64°
20
78°
63°
21
77°
64°
22
76°
62°
23
73°
61°
24
74°
59°
25
77°
61°
26
77°
56°
27
67°
52°
28
65°
49°
29
66°
52°
30
65°
50°
1
64°
51°
2
68°
58°
3
67°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Oak Lawn
Oak Lawn's September 2026 forecast shows daily high temperatures ranging from 64° to 94°, with overnight lows between 49° and 75°. The average high for September is 77° with an average low of 62°. 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 Oak Lawn. See also: October | November | December.
