S
M
T
W
T
F
S
28
77°
55°
29
80°
56°
30
78°
57°
1
79°
61°
2
93°
66°
3
92°
74°
4
87°
63°
5
84°
57°
6
75°
55°
7
74°
53°
8
72°
55°
9
77°
62°
10
74°
61°
11
77°
59°
12
73°
53°
13
79°
61°
14
83°
66°
15
78°
61°
16
79°
58°
17
77°
59°
18
75°
58°
19
76°
58°
20
75°
59°
21
74°
58°
22
75°
58°
23
74°
59°
24
75°
57°
25
74°
57°
26
74°
61°
27
75°
62°
28
75°
62°
29
74°
61°
30
75°
62°
31
76°
62°
1
74°
61°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
July Weather in Southwest Harbor
Southwest Harbor's July 2026 forecast shows daily high temperatures ranging from 72° to 83°, with overnight lows between 53° and 66°. The average high for July is 76° with an average low of 60°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how July weather will actually feel in Southwest Harbor. See also: August | September | October.