S
M
T
W
T
F
S
30
79°
66°
31
81°
70°
1
84°
70°
2
84°
69°
3
85°
63°
4
82°
61°
5
77°
62°
6
77°
68°
7
78°
67°
8
81°
68°
9
82°
66°
10
78°
67°
11
81°
66°
12
82°
67°
13
81°
67°
14
79°
66°
15
82°
67°
16
82°
63°
17
80°
66°
18
78°
60°
19
79°
58°
20
73°
57°
21
72°
55°
22
71°
62°
23
72°
59°
24
76°
56°
25
70°
55°
26
70°
55°
27
72°
56°
28
76°
61°
29
75°
59°
30
76°
57°
1
69°
60°
2
68°
52°
3
69°
58°
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 68° to 85°, with overnight lows between 52° and 70°. The average high for September is 77° with an average low of 62°. 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.
