S
M
T
W
T
F
S
26
90°
72°
27
91°
69°
28
91°
69°
29
93°
70°
30
92°
69°
31
90°
71°
1
91°
72°
2
92°
72°
3
93°
73°
4
94°
72°
5
93°
71°
6
90°
71°
7
89°
70°
8
91°
69°
9
93°
69°
10
89°
70°
11
93°
71°
12
91°
72°
13
89°
71°
14
89°
72°
15
90°
72°
16
90°
70°
17
93°
71°
18
92°
69°
19
88°
71°
20
88°
70°
21
90°
70°
22
91°
69°
23
88°
67°
24
87°
69°
25
90°
68°
26
88°
70°
27
90°
69°
28
90°
65°
29
85°
66°
30
85°
65°
31
86°
65°
1
86°
66°
2
87°
67°
3
88°
67°
4
89°
66°
5
88°
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 94°, with overnight lows between 65° and 73°. 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.
