Annual mean 12°C · wettest around December · prevailing wind W
Warmest
32.9 °C
Coldest
1.2 °C
Wettest
12%
Windiest
4.1 m/s
Prevailing
W
2.6 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Ontario over the whole year is 12°C. July is the hottest month, with highs of about 33°C; January is the coldest, with lows of about -3°C. Ontario has no sharply defined rainy season: the chance of rain on a given day runs from 2% in July, the driest month, to 12% in December, the wettest. Winds in Ontario are highest in May, averaging 3.3 m/s (12 km/h), and lightest in January, at 1.9 m/s (7 km/h). The prevailing wind is from the W. The clearest skies in Ontario come in July, when the sky is typically 3% covered; December is the cloudiest month, at 58%.
Month by month Ontario climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
2°C
-3°C
-2°C
9%
55%
1.9 m/s
0
0
5
February
5°C
-2°C
0°C
7%
47%
2.5 m/s
0
0
14
March
11°C
2°C
7°C
6%
41%
3.0 m/s
7
0
56
April
16°C
6°C
12°C
5%
32%
3.2 m/s
33
1
77
May
21°C
11°C
18°C
6%
25%
3.3 m/s
68
17
71
June
27°C
16°C
24°C
5%
15%
3.0 m/s
66
48
43
July
33°C
20°C
30°C
2%
3%
2.5 m/s
28
74
8
August
30°C
18°C
28°C
2%
6%
2.2 m/s
41
75
14
September
24°C
11°C
22°C
3%
13%
2.1 m/s
78
36
59
October
16°C
5°C
13°C
5%
23%
2.1 m/s
44
1
81
November
8°C
0°C
4°C
7%
35%
2.0 m/s
1
0
36
December
2°C
-2°C
-2°C
12%
58%
1.9 m/s
0
0
5
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Ontario weather by season
Year round, Ontario has days of about 2°C at their warmest in December, its coolest month, and 33°C in July, its warmest; the coolest hours of the day run from -3°C to 20°C through the year, and the average temperature over the year is 12°C around the clock. Rain is most likely around December and least likely around July. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Ontario weather in winterDecember to February
High 3°CLow -2°CRain 9%
Winter in Ontario has typical daily highs of about 3°C and lows of about -2°C, with a 9% chance of rain on a given day.
Ontario weather in springMarch to May
High 16°CLow 6°CRain 5%
Spring in Ontario has typical daily highs of about 16°C and lows of about 6°C, with a 5% chance of rain on a given day.
Ontario weather in summerJune to August
High 30°CLow 18°CRain 3%
Summer in Ontario has typical daily highs of about 30°C and lows of about 18°C, with a 3% chance of rain on a given day.
Ontario weather in autumnSeptember to November
High 16°CLow 5°CRain 5%
Autumn in Ontario has typical daily highs of about 16°C and lows of about 5°C, with a 5% chance of rain on a given day.
When is the rainy season in Ontario?
Ontario has no sharply defined rainy season: the chance of rain on a given day runs from 2% in July, the driest month, to 12% in December, the wettest.
What time of year is Ontario windiest?
Winds in Ontario are highest in May, averaging 3.3 m/s (12 km/h), and lightest in January, at 1.9 m/s (7 km/h). The prevailing wind is from the W.
What is the average temperature in Ontario year round?
The average temperature in Ontario over the whole year is 12°C. July is the hottest month, with highs of about 33°C; January is the coldest, with lows of about -3°C.