S
M
T
W
T
F
S
26
100°
68°
27
97°
65°
28
99°
66°
29
99°
63°
30
98°
64°
31
99°
67°
1
98°
66°
2
99°
67°
3
99°
66°
4
98°
66°
5
99°
65°
6
99°
66°
7
98°
66°
8
98°
65°
9
97°
66°
10
98°
65°
11
96°
65°
12
93°
64°
13
94°
61°
14
91°
59°
15
90°
61°
16
91°
65°
17
93°
61°
18
93°
60°
19
94°
61°
20
93°
63°
21
90°
64°
22
90°
65°
23
89°
65°
24
90°
64°
25
90°
62°
26
91°
59°
27
88°
58°
28
89°
59°
29
90°
61°
30
90°
60°
31
91°
58°
1
90°
59°
2
90°
58°
3
91°
57°
4
90°
56°
5
88°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Herndon
Herndon's August 2026 forecast shows daily high temperatures ranging from 88° to 100°, with overnight lows between 56° and 68°. The average high for August is 94° with an average low of 63°. 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 Herndon. See also: September | October | November.
