S
M
T
W
T
F
S
26
54°
39°
27
52°
37°
28
52°
40°
29
53°
42°
30
52°
43°
1
53°
42°
2
53°
42°
3
52°
41°
4
52°
41°
5
53°
42°
6
53°
39°
7
54°
41°
8
55°
43°
9
54°
43°
10
54°
42°
11
55°
44°
12
56°
44°
13
59°
43°
14
57°
42°
15
55°
40°
16
57°
43°
17
57°
42°
18
62°
46°
19
62°
47°
20
61°
45°
21
60°
40°
22
61°
41°
23
62°
47°
24
58°
46°
25
62°
46°
26
63°
47°
27
60°
46°
28
64°
47°
29
63°
46°
30
60°
44°
31
61°
42°
1
59°
43°
2
62°
47°
3
62°
43°
4
60°
47°
5
62°
45°
6
64°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Johnstone
Johnstone's May 2026 forecast shows daily high temperatures ranging from 52° to 64°, with overnight lows between 37° and 48°. The average high for May is 58° with an average low of 43°. 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 Johnstone. See also: June | July | August.
