S
M
T
W
T
F
S
30
99°
73°
31
98°
75°
1
98°
74°
2
96°
73°
3
95°
74°
4
95°
73°
5
96°
73°
6
98°
73°
7
102°
74°
8
103°
75°
9
102°
76°
10
102°
76°
11
94°
70°
12
93°
68°
13
92°
69°
14
88°
64°
15
89°
68°
16
91°
67°
17
91°
68°
18
90°
68°
19
91°
67°
20
90°
68°
21
90°
67°
22
89°
67°
23
90°
66°
24
90°
65°
25
89°
65°
26
89°
64°
27
90°
65°
28
90°
64°
29
89°
63°
30
89°
64°
1
88°
64°
2
88°
63°
3
87°
63°
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 87° to 103°, with overnight lows between 63° and 76°. The average high for September is 93° with an average low of 68°. 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.
