S
M
T
W
T
F
S
26
84°
64°
27
87°
68°
28
89°
71°
29
84°
69°
30
85°
68°
31
88°
65°
1
87°
65°
2
81°
74°
3
89°
74°
4
87°
70°
5
87°
73°
6
92°
70°
7
90°
71°
8
91°
72°
9
93°
68°
10
94°
70°
11
96°
70°
12
87°
67°
13
85°
66°
14
84°
63°
15
83°
63°
16
83°
63°
17
84°
65°
18
83°
63°
19
88°
65°
20
89°
68°
21
87°
67°
22
87°
68°
23
89°
69°
24
90°
69°
25
89°
68°
26
87°
68°
27
83°
67°
28
85°
67°
29
84°
66°
30
85°
67°
31
85°
66°
1
86°
65°
2
79°
59°
3
78°
60°
4
78°
61°
5
79°
59°
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 78° to 96°, with overnight lows between 59° and 72°. The average high for August is 86° with an average low of 66°. 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.
