S
M
T
W
T
F
S
26
64°
48°
27
70°
44°
28
62°
52°
29
58°
45°
30
57°
42°
1
N/A
2
50°
36°
3
59°
44°
4
71°
55°
5
59°
42°
6
53°
40°
7
51°
36°
8
56°
44°
9
59°
43°
10
64°
43°
11
62°
47°
12
64°
46°
13
64°
47°
14
62°
46°
15
67°
47°
16
63°
44°
17
66°
53°
18
73°
54°
19
72°
55°
20
73°
55°
21
74°
54°
22
74°
56°
23
75°
50°
24
66°
46°
25
66°
51°
26
72°
57°
27
74°
56°
28
68°
54°
29
68°
50°
30
69°
53°
31
71°
52°
1
69°
51°
2
72°
57°
3
71°
50°
4
69°
49°
5
69°
50°
6
70°
50°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
May Weather in Waterloo
Waterloo's May 2026 forecast shows daily high temperatures ranging from 50° to 75°, with overnight lows between 36° and 57°. The average high for May is 66° with an average low of 49°. 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.
