S
M
T
W
T
F
S
27
28°
18°
28
27°
20°
29
28°
21°
30
27°
12°
31
27°
13°
1
28°
12°
2
26°
9°
3
23°
8°
4
21°
15°
5
22°
13°
6
25°
13°
7
22°
14°
8
22°
8°
9
23°
15°
10
24°
17°
11
26°
13°
12
24°
12°
13
21°
12°
14
24°
9°
15
27°
7°
16
26°
6°
17
27°
5°
18
16°
8°
19
19°
10°
20
22°
9°
21
24°
7°
22
27°
6°
23
24°
6°
24
29°
20°
25
32°
17°
26
33°
14°
27
28°
8°
28
24°
6°
29
21°
10°
30
22°
10°
31
22°
5°
1
21°
11°
2
24°
5°
3
30°
4°
4
16°
5°
5
19°
0°
6
22°
8°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
January Weather in Waterloo
Waterloo's January 2027 forecast shows daily high temperatures ranging from 16° to 33°, with overnight lows between 0° and 21°. The average high for January is 24° with an average low of 11°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how January weather will actually feel in Waterloo. See also: February | March | April.