S
M
T
W
T
F
S
26
60°
41°
27
71°
37°
28
56°
44°
29
56°
50°
30
60°
40°
1
61°
32°
2
54°
37°
3
61°
36°
4
73°
33°
5
80°
52°
6
66°
45°
7
62°
40°
8
59°
47°
9
61°
45°
10
72°
51°
11
58°
39°
12
62°
44°
13
63°
51°
14
70°
50°
15
74°
52°
16
69°
48°
17
66°
50°
18
69°
49°
19
73°
51°
20
67°
45°
21
68°
46°
22
68°
46°
23
69°
48°
24
69°
46°
25
70°
49°
26
72°
51°
27
71°
49°
28
73°
48°
29
71°
48°
30
75°
52°
31
79°
57°
1
76°
55°
2
77°
51°
3
79°
58°
4
81°
59°
5
81°
59°
6
80°
60°
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 58° to 81°, with overnight lows between 39° and 60°. The average high for May is 70° with an average low of 50°. 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.
