S
M
T
W
T
F
S
27
78°
51°
28
79°
52°
29
80°
53°
30
79°
52°
1
81°
49°
2
79°
49°
3
83°
52°
4
79°
46°
5
82°
45°
6
78°
45°
7
Hist. Avg.
79°
47°
8
Hist. Avg.
79°
47°
9
Hist. Avg.
79°
47°
10
Hist. Avg.
78°
47°
11
Hist. Avg.
78°
46°
12
Hist. Avg.
78°
46°
13
Hist. Avg.
77°
46°
14
Hist. Avg.
77°
46°
15
Hist. Avg.
77°
46°
16
Hist. Avg.
76°
46°
17
Hist. Avg.
76°
45°
18
Hist. Avg.
76°
45°
19
Hist. Avg.
75°
45°
20
Hist. Avg.
75°
45°
21
Hist. Avg.
74°
45°
22
Hist. Avg.
74°
44°
23
Hist. Avg.
74°
44°
24
Hist. Avg.
73°
44°
25
Hist. Avg.
73°
44°
26
Hist. Avg.
73°
44°
27
Hist. Avg.
72°
44°
28
Hist. Avg.
72°
43°
29
Hist. Avg.
71°
43°
30
Hist. Avg.
71°
43°
31
Hist. Avg.
71°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
October Weather in Port Costa
Port Costa's October 2026 forecast shows daily high temperatures ranging from 78° to 83°, with overnight lows between 45° and 53°. The average high for October is 80° with an average low of 49°. 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 Port Costa. See also: November | December | January.
