S
M
T
W
T
F
S
27
36°
21°
28
32°
22°
29
35°
22°
30
35°
28°
31
38°
30°
1
49°
23°
2
45°
20°
3
35°
22°
4
30°
23°
5
35°
31°
6
44°
33°
7
46°
28°
8
49°
16°
9
48°
21°
10
28°
27°
11
37°
23°
12
38°
20°
13
32°
20°
14
32°
14°
15
33°
20°
16
28°
25°
17
38°
29°
18
37°
27°
19
47°
19°
20
43°
20°
21
29°
27°
22
35°
29°
23
41°
31°
24
43°
32°
25
43°
33°
26
45°
31°
27
46°
30°
28
43°
29°
29
44°
29°
30
41°
25°
31
35°
23°
1
46°
20°
2
Hist. Avg.
39°
24°
3
Hist. Avg.
39°
24°
4
Hist. Avg.
39°
24°
5
Hist. Avg.
39°
24°
6
Hist. Avg.
40°
24°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
January Weather in Islip
Islip's January 2027 forecast shows daily high temperatures ranging from 28° to 49°, with overnight lows between 14° and 33°. The average high for January is 39° with an average low of 25°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how January weather will actually feel in Islip. See also: February | March | April.
