S
M
T
W
T
F
S
30
86°
68°
31
87°
68°
1
87°
67°
2
86°
68°
3
87°
68°
4
87°
67°
5
84°
67°
6
85°
66°
7
85°
67°
8
87°
68°
9
87°
67°
10
85°
66°
11
85°
66°
12
84°
65°
13
81°
66°
14
76°
66°
15
82°
65°
16
83°
64°
17
78°
63°
18
78°
60°
19
74°
57°
20
74°
61°
21
81°
60°
22
81°
53°
23
71°
53°
24
73°
59°
25
71°
55°
26
79°
56°
27
81°
59°
28
79°
58°
29
78°
59°
30
79°
51°
1
77°
48°
2
68°
47°
3
67°
48°
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 67° to 87°, with overnight lows between 47° and 68°. 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.
