S
M
T
W
T
F
S
30
80°
67°
31
84°
67°
1
86°
66°
2
85°
67°
3
86°
63°
4
80°
65°
5
82°
66°
6
86°
66°
7
84°
65°
8
79°
62°
9
84°
66°
10
83°
65°
11
85°
57°
12
84°
62°
13
83°
64°
14
84°
64°
15
82°
63°
16
82°
62°
17
81°
63°
18
83°
62°
19
80°
63°
20
82°
55°
21
81°
52°
22
73°
57°
23
74°
59°
24
80°
59°
25
81°
60°
26
80°
55°
27
81°
52°
28
71°
51°
29
70°
52°
30
68°
50°
1
68°
50°
2
69°
58°
3
72°
57°
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 86°, with overnight lows between 50° and 67°. The average high for September is 80° with an average low of 60°. 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.
