S
M
T
W
T
F
S
26
64°
34°
27
68°
41°
28
60°
41°
29
47°
37°
30
47°
34°
1
45°
31°
2
51°
27°
3
56°
29°
4
73°
42°
5
57°
38°
6
50°
32°
7
49°
32°
8
61°
26°
9
57°
37°
10
54°
33°
11
52°
29°
12
58°
30°
13
51°
38°
14
66°
38°
15
71°
37°
16
79°
54°
17
76°
49°
18
82°
50°
19
77°
49°
20
59°
40°
21
59°
34°
22
66°
38°
23
56°
45°
24
70°
47°
25
81°
54°
26
86°
53°
27
82°
51°
28
76°
44°
29
71°
45°
30
69°
44°
31
70°
47°
1
71°
50°
2
73°
51°
3
74°
52°
4
72°
50°
5
70°
48°
6
69°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in St. Helen
St. Helen's May 2026 forecast shows daily high temperatures ranging from 56° to 86°, with overnight lows between 44° and 54°. The average high for May is 73° with an average low of 49°. 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 St. Helen. See also: June | July | August.
