S
M
T
W
T
F
S
26
64°
43°
27
59°
48°
28
57°
43°
29
63°
41°
30
68°
43°
1
64°
45°
2
61°
43°
3
55°
50°
4
59°
46°
5
55°
45°
6
55°
43°
7
59°
43°
8
61°
46°
9
63°
45°
10
59°
41°
11
54°
43°
12
55°
43°
13
52°
45°
14
55°
43°
15
52°
43°
16
52°
41°
17
57°
46°
18
59°
45°
19
N/A
20
62°
53°
21
67°
56°
22
69°
55°
23
66°
53°
24
69°
56°
25
71°
55°
26
69°
56°
27
71°
54°
28
69°
55°
29
65°
53°
30
65°
52°
31
66°
53°
1
60°
47°
2
60°
45°
3
62°
51°
4
61°
52°
5
64°
52°
6
66°
51°
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 60° to 71°, with overnight lows between 45° and 56°. The average high for May is 66° with an average low of 53°. 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.
