S
M
T
W
T
F
S
30
95°
72°
31
97°
74°
1
100°
73°
2
101°
72°
3
101°
74°
4
102°
73°
5
99°
73°
6
99°
75°
7
101°
72°
8
97°
74°
9
98°
71°
10
98°
69°
11
90°
74°
12
97°
72°
13
98°
70°
14
98°
70°
15
98°
74°
16
95°
67°
17
94°
67°
18
93°
66°
19
92°
68°
20
89°
69°
21
90°
68°
22
88°
64°
23
87°
63°
24
86°
61°
25
84°
61°
26
85°
60°
27
87°
63°
28
87°
65°
29
87°
64°
30
86°
65°
1
86°
64°
2
85°
63°
3
87°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sylvan
Sylvan's September 2026 forecast shows daily high temperatures ranging from 84° to 98°, with overnight lows between 60° and 74°. The average high for September is 89° with an average low of 65°. 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 Sylvan. See also: October | November | December.