S
M
T
W
T
F
S
26
81°
61°
27
73°
53°
28
67°
49°
29
84°
59°
30
77°
62°
1
69°
57°
2
66°
49°
3
70°
42°
4
80°
45°
5
82°
54°
6
86°
59°
7
80°
57°
8
72°
49°
9
72°
53°
10
84°
57°
11
79°
57°
12
71°
49°
13
80°
46°
14
78°
57°
15
76°
44°
16
84°
50°
17
90°
69°
18
90°
62°
19
90°
61°
20
91°
67°
21
90°
66°
22
87°
66°
23
73°
66°
24
80°
62°
25
85°
66°
26
85°
69°
27
86°
70°
28
89°
70°
29
84°
68°
30
86°
69°
31
72°
64°
1
84°
64°
2
73°
54°
3
77°
52°
4
82°
52°
5
85°
55°
6
86°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
May Weather in Waterloo
Waterloo's May 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for May is ° with an average low of °. 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 Waterloo. See also: June | July | August.
