S
M
T
W
T
F
S
31
66°
41°
1
78°
43°
2
81°
48°
3
69°
52°
4
64°
50°
5
63°
48°
6
60°
46°
7
62°
47°
8
57°
49°
9
62°
51°
10
65°
46°
11
67°
43°
12
74°
45°
13
80°
48°
14
84°
52°
15
70°
54°
16
73°
50°
17
71°
46°
18
76°
46°
19
77°
49°
20
69°
47°
21
73°
49°
22
86°
47°
23
87°
54°
24
79°
53°
25
63°
53°
26
65°
50°
27
68°
51°
28
68°
51°
29
66°
50°
30
65°
52°
1
68°
50°
2
67°
49°
3
68°
50°
4
70°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
June Weather in San Juan Island
San Juan Island's June 2026 forecast shows daily high temperatures ranging from 63° to 70°, with overnight lows between 49° and 53°. The average high for June is 67° with an average low of 51°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how June weather will actually feel in San Juan Island. See also: July | August | September.
