S
M
T
W
T
F
S
26
64°
43°
27
59°
48°
28
57°
43°
29
63°
41°
30
N/A
1
66°
44°
2
65°
51°
3
57°
46°
4
58°
44°
5
56°
42°
6
54°
40°
7
57°
41°
8
60°
43°
9
62°
45°
10
62°
47°
11
63°
49°
12
64°
48°
13
58°
42°
14
59°
41°
15
63°
48°
16
64°
47°
17
61°
46°
18
63°
48°
19
60°
47°
20
60°
46°
21
61°
45°
22
61°
44°
23
62°
43°
24
61°
43°
25
60°
44°
26
60°
43°
27
63°
47°
28
62°
50°
29
66°
49°
30
62°
45°
31
61°
44°
1
60°
44°
2
61°
45°
3
61°
44°
4
62°
44°
5
61°
45°
6
62°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Runcorn
Runcorn's May 2026 forecast shows daily high temperatures ranging from 54° to 66°, with overnight lows between 40° and 51°. The average high for May is 61° with an average low of 45°. 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 Runcorn. See also: June | July | August.
