S
M
T
W
T
F
S
26
88°
70°
27
89°
69°
28
89°
71°
29
88°
71°
30
89°
70°
31
87°
68°
1
84°
69°
2
88°
68°
3
88°
69°
4
89°
71°
5
88°
71°
6
89°
69°
7
86°
67°
8
88°
68°
9
87°
67°
10
88°
61°
11
82°
63°
12
83°
64°
13
85°
61°
14
85°
63°
15
82°
65°
16
80°
68°
17
82°
67°
18
82°
65°
19
83°
65°
20
80°
64°
21
80°
67°
22
81°
66°
23
81°
63°
24
82°
66°
25
86°
61°
26
86°
60°
27
80°
60°
28
80°
63°
29
81°
65°
30
78°
64°
31
82°
65°
1
81°
59°
2
78°
58°
3
78°
58°
4
79°
57°
5
77°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Johnston
Johnston's August 2026 forecast shows daily high temperatures ranging from 77° to 89°, with overnight lows between 57° and 71°. The average high for August is 84° with an average low of 65°. 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 Johnston. See also: September | October | November.
