S
M
T
W
T
F
S
30
97°
71°
31
95°
67°
1
96°
69°
2
94°
67°
3
87°
65°
4
90°
65°
5
94°
67°
6
94°
66°
7
95°
66°
8
95°
67°
9
94°
68°
10
90°
68°
11
88°
68°
12
88°
67°
13
89°
68°
14
90°
67°
15
86°
67°
16
85°
66°
17
86°
66°
18
89°
65°
19
88°
65°
20
87°
64°
21
90°
65°
22
92°
64°
23
89°
64°
24
90°
65°
25
90°
64°
26
88°
64°
27
85°
63°
28
82°
62°
29
81°
61°
30
84°
56°
1
83°
53°
2
79°
52°
3
78°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Lewisville
Lewisville's September 2026 forecast shows daily high temperatures ranging from 78° to 97°, with overnight lows between 52° and 71°. The average high for September is 89° with an average low of 64°. 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 Lewisville. See also: October | November | December.
