S
M
T
W
T
F
S
26
88°
52°
27
87°
54°
28
88°
56°
29
92°
56°
30
93°
55°
31
89°
53°
1
87°
54°
2
88°
53°
3
84°
54°
4
91°
54°
5
87°
55°
6
89°
52°
7
83°
52°
8
86°
53°
9
87°
56°
10
91°
55°
11
91°
56°
12
92°
55°
13
93°
56°
14
92°
53°
15
85°
51°
16
84°
51°
17
84°
53°
18
88°
57°
19
88°
53°
20
87°
51°
21
84°
53°
22
85°
53°
23
88°
54°
24
88°
51°
25
82°
52°
26
87°
54°
27
82°
49°
28
82°
50°
29
84°
53°
30
86°
48°
31
82°
47°
1
79°
48°
2
81°
48°
3
84°
53°
4
85°
50°
5
85°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Johnstown
Johnstown's August 2026 forecast shows daily high temperatures ranging from 79° to 93°, with overnight lows between 47° and 57°. The average high for August is 87° with an average low of 53°. 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 Johnstown. See also: September | October | November.
