S
M
T
W
T
F
S
30
80°
63°
31
80°
67°
1
79°
67°
2
79°
66°
3
81°
66°
4
82°
68°
5
85°
67°
6
86°
68°
7
86°
67°
8
85°
66°
9
84°
66°
10
84°
67°
11
83°
67°
12
84°
66°
13
81°
65°
14
78°
64°
15
76°
64°
16
75°
63°
17
76°
62°
18
79°
63°
19
80°
62°
20
79°
63°
21
81°
61°
22
82°
56°
23
81°
55°
24
74°
60°
25
72°
57°
26
71°
59°
27
78°
58°
28
79°
59°
29
81°
58°
30
81°
57°
1
79°
54°
2
78°
56°
3
79°
56°
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 71° to 86°, with overnight lows between 54° and 68°. The average high for September is 80° 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 McLean. See also: October | November | December.
