S
M
T
W
T
F
S
26
90°
72°
27
91°
69°
28
91°
69°
29
93°
70°
30
92°
69°
31
94°
70°
1
95°
69°
2
94°
69°
3
92°
72°
4
90°
68°
5
90°
69°
6
91°
68°
7
89°
68°
8
89°
69°
9
90°
69°
10
89°
70°
11
89°
71°
12
90°
69°
13
93°
70°
14
94°
70°
15
93°
71°
16
92°
68°
17
88°
70°
18
92°
69°
19
89°
68°
20
88°
67°
21
89°
69°
22
87°
69°
23
87°
70°
24
91°
71°
25
89°
70°
26
90°
71°
27
90°
71°
28
88°
70°
29
86°
71°
30
90°
67°
31
90°
66°
1
86°
66°
2
86°
68°
3
85°
67°
4
85°
68°
5
89°
69°
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 85° to 95°, with overnight lows between 66° and 72°. The average high for August is 90° with an average low of 69°. 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.
