S
M
T
W
T
F
S
26
79°
66°
27
79°
70°
28
78°
70°
29
81°
68°
30
81°
69°
31
82°
68°
1
81°
69°
2
83°
69°
3
81°
68°
4
82°
70°
5
83°
71°
6
82°
68°
7
82°
72°
8
80°
71°
9
82°
71°
10
83°
70°
11
79°
68°
12
78°
70°
13
79°
71°
14
81°
71°
15
82°
70°
16
81°
71°
17
79°
71°
18
80°
70°
19
80°
69°
20
81°
70°
21
82°
70°
22
81°
69°
23
78°
68°
24
82°
69°
25
83°
70°
26
83°
69°
27
82°
68°
28
79°
66°
29
77°
66°
30
77°
67°
31
79°
67°
1
81°
66°
2
81°
68°
3
79°
63°
4
75°
63°
5
75°
66°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Islip
Islip's August 2026 forecast shows daily high temperatures ranging from 75° to 83°, with overnight lows between 63° and 72°. The average high for August is 80° with an average low of 69°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Islip. See also: September | October | November.
