Waterloo Weather

Waterloo has a humid continental climate of the warm summer subtype ; this means that there are large seasonal differences, usually very warm to hot (and humid) summers and cold (to very cold) winters. Compared to the rest of Canada, it has moderate weather. Winter temperatures generally last from the middle of December until the middle of March, while summer temperatures generally occur between the middle of May to close to the end of September. Temperatures can exceed 30℃ (86℉) several times a year. Waterloo has approximately 140 frost-free days per year.

Average Temperature
Jan
23 °F
-5 °C
Feb
27 °F
-3 °C
Mar
34 °F
1 °C
Apr
45 °F
7 °C
May
61 °F
16 °C
Jun
70 °F
21 °C
Jul
77 °F
25 °C
Aug
75 °F
24 °C
Sep
68 °F
20 °C
Oct
55 °F
13 °C
Nov
37 °F
3 °C
Dec
32 °F
0 °C
Humidity
Jan
63%
Feb
69%
Mar
61%
Apr
70%
May
75%
Jun
73%
Jul
78%
Aug
74%
Sep
79%
Oct
76%
Nov
76%
Dec
72%
Rain
Jan
45mm
Feb
43mm
Mar
32mm
Apr
82mm
May
119mm
Jun
191mm
Jul
76mm
Aug
70mm
Sep
60mm
Oct
87mm
Nov
47mm
Dec
38mm
Clouds
Jan
66%
Feb
82%
Mar
54%
Apr
72%
May
70%
Jun
46%
Jul
28%
Aug
27%
Sep
49%
Oct
57%
Nov
78%
Dec
70%
Air quality US AQI
Jan
30
Feb
33
Mar
21
Apr
23
May
26
Jun
27
Jul
29
Aug
27
Sep
25
Oct
22
Nov
26
Dec
32
Sun
Jan
1UVI
Feb
2UVI
Mar
3UVI
Apr
4UVI
May
6UVI
Jun
7UVI
Jul
8UVI
Aug
7UVI
Sep
5UVI
Oct
4UVI
Nov
2UVI
Dec
1UVI