S
M
T
W
T
F
S
30
81°
69°
31
91°
72°
1
95°
75°
2
96°
75°
3
91°
73°
4
91°
73°
5
84°
68°
6
82°
68°
7
82°
65°
8
77°
67°
9
79°
66°
10
79°
64°
11
76°
61°
12
78°
60°
13
77°
63°
14
78°
60°
15
81°
65°
16
81°
65°
17
80°
64°
18
79°
65°
19
81°
65°
20
81°
64°
21
80°
65°
22
80°
64°
23
80°
64°
24
80°
63°
25
79°
64°
26
80°
63°
27
79°
62°
28
78°
62°
29
77°
61°
30
77°
61°
1
76°
60°
2
77°
60°
3
77°
59°
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 76° to 96°, with overnight lows between 59° and 75°. The average high for September is 81° with an average low of 65°. 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.
