S
M
T
W
T
F
S
28
80°
66°
29
87°
63°
30
85°
65°
1
84°
69°
2
96°
73°
3
98°
75°
4
96°
72°
5
81°
68°
6
69°
64°
7
70°
63°
8
80°
63°
9
82°
68°
10
85°
72°
11
82°
66°
12
83°
65°
13
81°
63°
14
85°
69°
15
92°
74°
16
86°
72°
17
84°
66°
18
79°
68°
19
80°
63°
20
78°
60°
21
78°
66°
22
N/A
23
79°
61°
24
81°
63°
25
81°
64°
26
80°
66°
27
81°
68°
28
83°
69°
29
80°
68°
30
81°
67°
31
83°
67°
1
82°
69°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
July Weather in Port Jefferson
Port Jefferson's July 2026 forecast shows daily high temperatures ranging from 79° to 83°, with overnight lows between 61° and 69°. The average high for July is 81° with an average low of 66°. 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.
