S
M
T
W
T
F
S
30
86°
55°
31
90°
56°
1
90°
59°
2
85°
54°
3
84°
54°
4
84°
55°
5
85°
56°
6
85°
55°
7
84°
55°
8
85°
57°
9
84°
58°
10
85°
61°
11
86°
60°
12
87°
60°
13
86°
62°
14
89°
62°
15
90°
60°
16
90°
59°
17
89°
58°
18
89°
58°
19
88°
57°
20
86°
59°
21
88°
59°
22
88°
58°
23
87°
59°
24
83°
59°
25
79°
58°
26
78°
59°
27
81°
58°
28
80°
59°
29
81°
58°
30
80°
59°
1
83°
56°
2
80°
56°
3
84°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Castle Hill
Castle Hill's September 2026 forecast shows daily high temperatures ranging from 78° to 90°, with overnight lows between 54° and 62°. The average high for September is 85° with an average low of 58°. 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 Castle Hill. See also: October | November | December.
