S
M
T
W
T
F
S
30
95°
71°
31
96°
70°
1
93°
69°
2
89°
70°
3
89°
68°
4
90°
68°
5
93°
69°
6
94°
68°
7
94°
68°
8
93°
70°
9
91°
70°
10
90°
69°
11
88°
70°
12
90°
69°
13
91°
70°
14
93°
71°
15
90°
70°
16
89°
70°
17
90°
69°
18
92°
69°
19
92°
67°
20
91°
68°
21
89°
69°
22
91°
68°
23
90°
69°
24
89°
68°
25
86°
68°
26
86°
67°
27
87°
67°
28
88°
66°
29
85°
65°
30
85°
61°
1
86°
59°
2
82°
58°
3
81°
58°
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 81° to 96°, with overnight lows between 58° and 71°. The average high for September is 90° 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.
