S
M
T
W
T
F
S
27
68°
55°
28
77°
55°
29
89°
49°
30
79°
54°
1
87°
51°
2
78°
54°
3
86°
58°
4
96°
63°
5
97°
61°
6
98°
58°
7
83°
58°
8
93°
55°
9
74°
54°
10
63°
57°
11
69°
46°
12
72°
45°
13
78°
44°
14
72°
45°
15
87°
48°
16
94°
52°
17
83°
55°
18
76°
50°
19
67°
55°
20
72°
47°
21
64°
54°
22
59°
53°
23
72°
55°
24
72°
50°
25
70°
53°
26
68°
50°
27
68°
50°
28
66°
52°
29
65°
56°
30
66°
53°
31
72°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
October Weather in Castro Valley
Castro Valley's October 2026 forecast shows daily high temperatures ranging from 65° to 72°, with overnight lows between 50° and 56°. The average high for October is 68° with an average low of 52°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how October weather will actually feel in Castro Valley. See also: November | December | January.
