S
M
T
W
T
F
S
30
89°
72°
31
87°
73°
1
98°
77°
2
91°
74°
3
91°
71°
4
90°
73°
5
83°
65°
6
81°
62°
7
81°
64°
8
84°
67°
9
92°
69°
10
92°
67°
11
83°
61°
12
85°
66°
13
89°
63°
14
84°
59°
15
81°
59°
16
85°
60°
17
83°
59°
18
74°
56°
19
77°
57°
20
81°
61°
21
78°
62°
22
79°
62°
23
77°
61°
24
77°
58°
25
76°
60°
26
79°
61°
27
79°
60°
28
75°
55°
29
70°
52°
30
72°
55°
1
71°
56°
2
71°
55°
3
68°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in McLean
McLean's September 2026 forecast shows daily high temperatures ranging from 68° to 92°, with overnight lows between 52° and 73°. The average high for September is 80° with an average low of 61°. 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 McLean. See also: October | November | December.
