S
M
T
W
T
F
S
26
71°
37°
27
57°
39°
28
58°
45°
29
72°
40°
30
81°
44°
1
71°
49°
2
76°
51°
3
89°
55°
4
79°
49°
5
75°
49°
6
75°
48°
7
72°
48°
8
66°
49°
9
73°
50°
10
76°
51°
11
74°
50°
12
73°
49°
13
70°
50°
14
66°
46°
15
66°
46°
16
62°
47°
17
62°
45°
18
63°
45°
19
63°
48°
20
64°
46°
21
63°
49°
22
63°
44°
23
67°
45°
24
72°
50°
25
73°
51°
26
72°
49°
27
65°
47°
28
66°
46°
29
67°
50°
30
70°
52°
31
64°
49°
1
64°
48°
2
65°
47°
3
64°
48°
4
64°
45°
5
66°
46°
6
68°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in St. Helens
St. Helens's May 2026 forecast shows daily high temperatures ranging from 62° to 89°, with overnight lows between 44° and 55°. The average high for May is 69° with an average low of 48°. 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. Helens. See also: June | July | August.
