S
M
T
W
T
F
S
30
101°
81°
31
100°
83°
1
100°
82°
2
100°
76°
3
89°
75°
4
95°
76°
5
98°
76°
6
100°
79°
7
99°
80°
8
102°
77°
9
101°
80°
10
100°
77°
11
97°
75°
12
97°
76°
13
95°
77°
14
94°
75°
15
90°
69°
16
94°
73°
17
93°
74°
18
85°
70°
19
87°
73°
20
92°
73°
21
92°
72°
22
91°
72°
23
92°
73°
24
92°
72°
25
91°
70°
26
90°
67°
27
81°
61°
28
81°
61°
29
80°
62°
30
85°
65°
1
89°
68°
2
89°
62°
3
79°
58°
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 79° to 102°, with overnight lows between 58° and 80°. The average high for September is 92° with an average low of 72°. 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.
