S
M
T
W
T
F
S
30
101°
77°
31
102°
77°
1
101°
76°
2
103°
74°
3
94°
78°
4
99°
78°
5
100°
74°
6
101°
75°
7
101°
76°
8
102°
79°
9
101°
79°
10
100°
77°
11
102°
76°
12
102°
76°
13
101°
79°
14
102°
77°
15
102°
79°
16
100°
78°
17
101°
76°
18
98°
72°
19
98°
76°
20
101°
77°
21
99°
74°
22
99°
71°
23
99°
72°
24
97°
73°
25
96°
72°
26
94°
69°
27
95°
72°
28
98°
74°
29
95°
76°
30
92°
76°
1
86°
70°
2
78°
69°
3
76°
66°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Waco
Waco's September 2026 forecast shows daily high temperatures ranging from 76° to 95°, with overnight lows between 66° and 76°. The average high for September is 85° with an average low of 71°. 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 Waco. See also: October | November | December.