S
M
T
W
T
F
S
30
92°
69°
31
92°
71°
1
93°
72°
2
92°
67°
3
91°
66°
4
89°
66°
5
89°
67°
6
90°
70°
7
92°
71°
8
96°
72°
9
95°
72°
10
97°
70°
11
96°
70°
12
92°
71°
13
95°
71°
14
96°
66°
15
90°
65°
16
89°
64°
17
88°
65°
18
89°
66°
19
89°
68°
20
88°
67°
21
87°
68°
22
87°
69°
23
88°
68°
24
87°
68°
25
86°
67°
26
86°
68°
27
88°
67°
28
87°
67°
29
86°
66°
30
85°
67°
1
84°
65°
2
85°
66°
3
89°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Castroville
Castroville's September 2026 forecast shows daily high temperatures ranging from 84° to 97°, with overnight lows between 61° and 72°. The average high for September is 90° with an average low of 68°. 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 Castroville. See also: October | November | December.
