S
M
T
W
T
F
S
26
70°
48°
27
82°
41°
28
72°
50°
29
66°
50°
30
54°
37°
1
64°
34°
2
52°
34°
3
59°
30°
4
72°
46°
5
71°
54°
6
59°
47°
7
53°
35°
8
60°
44°
9
63°
47°
10
66°
52°
11
53°
40°
12
50°
40°
13
56°
49°
14
63°
54°
15
67°
56°
16
67°
56°
17
69°
55°
18
64°
50°
19
66°
54°
20
70°
55°
21
68°
54°
22
66°
48°
23
60°
46°
24
62°
48°
25
63°
50°
26
64°
49°
27
63°
48°
28
64°
48°
29
64°
49°
30
65°
51°
31
70°
58°
1
68°
57°
2
67°
54°
3
67°
53°
4
69°
57°
5
71°
56°
6
75°
59°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Helvetia
Helvetia's May 2026 forecast shows daily high temperatures ranging from 50° to 75°, with overnight lows between 35° and 59°. The average high for May is 64° with an average low of 51°. 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 Helvetia. See also: June | July | August.