S
M
T
W
T
F
S
28
86°
70°
29
91°
73°
30
91°
72°
1
94°
71°
2
93°
71°
3
95°
69°
4
95°
69°
5
87°
70°
6
84°
69°
7
88°
64°
8
90°
66°
9
88°
67°
10
86°
69°
11
79°
65°
12
89°
62°
13
91°
62°
14
91°
63°
15
91°
66°
16
91°
71°
17
91°
71°
18
90°
68°
19
83°
56°
20
84°
56°
21
87°
59°
22
72°
59°
23
77°
55°
24
76°
57°
25
82°
58°
26
82°
68°
27
85°
68°
28
86°
62°
29
79°
57°
30
81°
60°
31
80°
62°
1
81°
63°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
July Weather in Port Jefferson
Port Jefferson's July 2026 forecast shows daily high temperatures ranging from 79° to 86°, with overnight lows between 57° and 68°. The average high for July is 82° with an average low of 63°. 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 Port Jefferson. See also: August | September | October.
