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
74°
54°
5
62°
44°
6
60°
41°
7
63°
38°
8
68°
49°
9
74°
48°
10
69°
48°
11
72°
43°
12
78°
45°
13
69°
44°
14
69°
53°
15
75°
63°
16
81°
64°
17
86°
64°
18
80°
65°
19
75°
57°
20
72°
55°
21
74°
54°
22
73°
54°
23
72°
54°
24
74°
56°
25
79°
60°
26
78°
56°
27
78°
62°
28
80°
61°
29
81°
61°
30
75°
57°
31
74°
56°
1
74°
56°
2
75°
54°
3
74°
57°
4
76°
61°
5
82°
64°
6
84°
65°
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 69° to 86°, with overnight lows between 44° and 65°. The average high for May is 76° with an average low of 58°. 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.
