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
57°
41°
14
56°
45°
15
63°
43°
16
77°
58°
17
79°
50°
18
87°
60°
19
87°
67°
20
78°
43°
21
62°
40°
22
63°
44°
23
69°
49°
24
70°
53°
25
68°
51°
26
71°
50°
27
72°
53°
28
74°
54°
29
70°
49°
30
72°
54°
31
71°
53°
1
70°
51°
2
68°
51°
3
67°
50°
4
67°
54°
5
71°
54°
6
73°
52°
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 62° to 87°, with overnight lows between 40° and 67°. The average high for May is 72° with an average low of 52°. 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.
