S
M
T
W
T
F
S
26
80°
65°
27
83°
65°
28
84°
64°
29
83°
64°
30
82°
63°
31
78°
61°
1
77°
63°
2
82°
65°
3
84°
66°
4
85°
66°
5
84°
65°
6
84°
65°
7
80°
60°
8
81°
61°
9
81°
56°
10
77°
54°
11
76°
56°
12
77°
57°
13
77°
56°
14
76°
56°
15
75°
57°
16
77°
61°
17
79°
59°
18
78°
58°
19
77°
58°
20
77°
62°
21
76°
61°
22
79°
60°
23
78°
61°
24
80°
61°
25
82°
60°
26
83°
61°
27
83°
56°
28
81°
54°
29
76°
60°
30
75°
57°
31
76°
53°
1
75°
54°
2
74°
52°
3
73°
50°
4
73°
51°
5
74°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
August Weather in Waterloo
Waterloo's August 2026 forecast shows daily high temperatures ranging from 73° to 85°, with overnight lows between 50° and 66°. The average high for August is 79° with an average low of 59°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how August weather will actually feel in Waterloo. See also: September | October | November.
