S
M
T
W
T
F
S
30
95°
72°
31
95°
73°
1
93°
72°
2
94°
70°
3
91°
71°
4
90°
72°
5
90°
71°
6
91°
72°
7
94°
72°
8
93°
71°
9
93°
71°
10
94°
72°
11
93°
72°
12
93°
71°
13
92°
71°
14
92°
69°
15
88°
70°
16
89°
70°
17
89°
69°
18
87°
70°
19
88°
70°
20
87°
69°
21
90°
70°
22
88°
69°
23
86°
65°
24
91°
64°
25
86°
63°
26
86°
65°
27
88°
69°
28
90°
68°
29
Hist. Avg.
86°
66°
30
Hist. Avg.
86°
66°
1
Hist. Avg.
86°
65°
2
Hist. Avg.
85°
65°
3
Hist. Avg.
85°
65°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Katy
Katy's September 2026 forecast shows daily high temperatures ranging from 86° to 95°, with overnight lows between 63° and 73°. The average high for September is 91° with an average low of 70°. 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 Katy. See also: October | November | December.
