S
M
T
W
T
F
S
26
77°
49°
27
63°
57°
28
64°
53°
29
63°
43°
30
62°
40°
1
56°
43°
2
57°
41°
3
66°
43°
4
75°
56°
5
60°
46°
6
58°
41°
7
61°
43°
8
68°
50°
9
72°
55°
10
67°
48°
11
63°
44°
12
67°
50°
13
72°
55°
14
71°
49°
15
71°
53°
16
73°
55°
17
77°
53°
18
74°
59°
19
78°
58°
20
74°
53°
21
76°
51°
22
70°
50°
23
70°
50°
24
71°
52°
25
70°
51°
26
70°
51°
27
72°
52°
28
73°
55°
29
74°
56°
30
76°
60°
31
77°
61°
1
75°
55°
2
76°
56°
3
77°
62°
4
78°
61°
5
80°
63°
6
82°
64°
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 82°, with overnight lows between 41° and 64°. The average high for May is 72° 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 May weather will actually feel in Johnstown. See also: June | July | August.
