S
M
T
W
T
F
S
26
74°
45°
27
74°
49°
28
60°
46°
29
59°
39°
30
55°
35°
1
55°
35°
2
60°
32°
3
76°
47°
4
82°
43°
5
59°
42°
6
57°
35°
7
65°
39°
8
70°
46°
9
79°
46°
10
65°
42°
11
68°
50°
12
71°
46°
13
74°
50°
14
76°
51°
15
77°
52°
16
69°
50°
17
70°
52°
18
75°
53°
19
73°
52°
20
66°
49°
21
67°
46°
22
66°
47°
23
67°
48°
24
68°
51°
25
69°
55°
26
69°
52°
27
70°
54°
28
72°
51°
29
74°
53°
30
77°
56°
31
78°
59°
1
77°
55°
2
77°
59°
3
80°
60°
4
81°
61°
5
80°
61°
6
74°
60°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Marengo
Marengo's May 2026 forecast shows daily high temperatures ranging from 57° to 81°, with overnight lows between 35° and 61°. The average high for May is 72° 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 Marengo. See also: June | July | August.