S
M
T
W
T
F
S
27
61°
44°
28
63°
44°
29
57°
46°
30
61°
42°
1
60°
46°
2
66°
53°
3
65°
50°
4
66°
50°
5
56°
47°
6
60°
46°
7
65°
44°
8
63°
45°
9
59°
48°
10
58°
46°
11
61°
44°
12
58°
41°
13
57°
49°
14
62°
52°
15
61°
47°
16
63°
45°
17
63°
43°
18
56°
41°
19
57°
41°
20
58°
41°
21
59°
41°
22
56°
43°
23
56°
42°
24
51°
44°
25
57°
47°
26
58°
44°
27
56°
45°
28
55°
44°
29
57°
46°
30
55°
45°
31
54°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
October Weather in San Juan Island
San Juan Island's October 2026 forecast shows daily high temperatures ranging from 51° to 58°, with overnight lows between 42° and 47°. The average high for October is 56° with an average low of 45°. 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 San Juan Island. See also: November | December | January.
