S
M
T
W
T
F
S
26
69°
43°
27
N/A
28
70°
49°
29
74°
41°
30
70°
47°
31
68°
47°
1
68°
51°
2
69°
48°
3
70°
51°
4
70°
52°
5
69°
51°
6
69°
51°
7
68°
53°
8
69°
52°
9
68°
55°
10
70°
57°
11
72°
55°
12
67°
54°
13
67°
51°
14
68°
52°
15
67°
51°
16
68°
51°
17
68°
52°
18
69°
55°
19
68°
55°
20
72°
54°
21
73°
58°
22
69°
52°
23
68°
54°
24
69°
58°
25
71°
57°
26
69°
53°
27
69°
53°
28
70°
54°
29
70°
53°
30
71°
54°
31
75°
59°
1
75°
59°
2
74°
58°
3
75°
60°
4
76°
59°
5
70°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Long Island
Long Island's August 2026 forecast shows daily high temperatures ranging from 67° to 76°, with overnight lows between 41° and 60°. The average high for August is 70° with an average low of 53°. 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 Long Island. See also: September | October | November.
