S
M
T
W
T
F
S
27
72°
60°
28
73°
60°
29
74°
52°
30
70°
52°
1
66°
57°
2
67°
57°
3
71°
56°
4
72°
58°
5
71°
58°
6
72°
59°
7
71°
58°
8
72°
55°
9
73°
54°
10
70°
51°
11
66°
52°
12
65°
54°
13
62°
53°
14
62°
52°
15
65°
53°
16
67°
54°
17
69°
50°
18
70°
44°
19
60°
45°
20
60°
42°
21
61°
44°
22
58°
51°
23
63°
49°
24
66°
45°
25
59°
43°
26
58°
42°
27
57°
49°
28
60°
42°
29
64°
40°
30
64°
39°
31
67°
47°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
October Weather in Port Jefferson
Port Jefferson's October 2026 forecast shows daily high temperatures ranging from 57° to 74°, with overnight lows between 39° and 60°. The average high for October is 66° 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 October weather will actually feel in Port Jefferson. See also: November | December | January.