S
M
T
W
T
F
S
26
65°
37°
27
70°
39°
28
68°
42°
29
64°
47°
30
54°
40°
1
56°
35°
2
50°
33°
3
53°
33°
4
69°
38°
5
78°
49°
6
55°
42°
7
54°
36°
8
52°
37°
9
49°
35°
10
60°
41°
11
56°
33°
12
58°
32°
13
56°
47°
14
58°
47°
15
62°
46°
16
75°
57°
17
77°
47°
18
77°
57°
19
83°
60°
20
71°
47°
21
64°
43°
22
64°
46°
23
64°
47°
24
65°
48°
25
64°
50°
26
69°
48°
27
62°
47°
28
64°
45°
29
66°
51°
30
66°
53°
31
72°
50°
1
66°
48°
2
67°
46°
3
66°
46°
4
67°
47°
5
69°
54°
6
70°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Johnstown
Johnstown's May 2026 forecast shows daily high temperatures ranging from 56° to 83°, with overnight lows between 43° and 60°. The average high for May is 67° with an average low of 49°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how May weather will actually feel in Johnstown. See also: June | July | August.
