S
M
T
W
T
F
S
26
83°
61°
27
82°
64°
28
84°
65°
29
84°
65°
30
83°
64°
31
82°
65°
1
83°
65°
2
82°
64°
3
83°
64°
4
82°
63°
5
83°
62°
6
81°
62°
7
82°
64°
8
84°
58°
9
76°
57°
10
75°
56°
11
76°
60°
12
76°
62°
13
78°
62°
14
78°
63°
15
79°
63°
16
81°
60°
17
79°
56°
18
76°
55°
19
76°
59°
20
77°
60°
21
79°
61°
22
81°
59°
23
80°
59°
24
80°
55°
25
74°
55°
26
74°
54°
27
72°
54°
28
72°
53°
29
74°
53°
30
74°
56°
31
76°
60°
1
79°
60°
2
79°
59°
3
80°
52°
4
77°
50°
5
72°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Old Tappan
Old Tappan's August 2026 forecast shows daily high temperatures ranging from 72° to 84°, with overnight lows between 50° and 65°. The average high for August is 79° with an average low of 59°. 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 Old Tappan. See also: September | October | November.