S
M
T
W
T
F
S
26
67°
38°
27
73°
37°
28
69°
48°
29
58°
44°
30
50°
38°
1
53°
30°
2
50°
36°
3
59°
36°
4
70°
44°
5
72°
47°
6
54°
43°
7
54°
36°
8
55°
40°
9
67°
32°
10
54°
38°
11
54°
32°
12
56°
32°
13
48°
44°
14
54°
42°
15
63°
42°
16
74°
46°
17
76°
51°
18
83°
48°
19
85°
66°
20
70°
45°
21
59°
39°
22
68°
33°
23
68°
49°
24
56°
52°
25
77°
54°
26
81°
57°
27
76°
49°
28
67°
47°
29
63°
47°
30
66°
44°
31
68°
48°
1
72°
50°
2
73°
52°
3
71°
51°
4
73°
52°
5
71°
49°
6
74°
49°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Marathon
Marathon's May 2026 forecast shows daily high temperatures ranging from 56° to 81°, with overnight lows between 44° and 57°. The average high for May is 70° with an average low of 50°. 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 Marathon. See also: June | July | August.
