S
M
T
W
T
F
S
30
89°
72°
31
87°
73°
1
98°
77°
2
91°
74°
3
91°
71°
4
90°
72°
5
85°
72°
6
85°
66°
7
84°
64°
8
86°
64°
9
89°
70°
10
91°
74°
11
82°
70°
12
81°
71°
13
89°
74°
14
81°
65°
15
78°
58°
16
83°
64°
17
87°
70°
18
88°
73°
19
81°
67°
20
84°
73°
21
74°
65°
22
65°
59°
23
66°
56°
24
67°
53°
25
76°
54°
26
69°
56°
27
65°
58°
28
68°
60°
29
76°
58°
30
80°
60°
1
82°
62°
2
83°
59°
3
72°
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 65° to 83°, with overnight lows between 56° and 62°. The average high for September is 74° with an average low of 59°. 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.
