Annual mean 10°C · wettest around December · prevailing wind W
Warmest
25.3 °C
Coldest
-1.8 °C
Wettest
17%
Windiest
4.8 m/s
Prevailing
W
4.1 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 10°C. July is the hottest month, with highs of about 25°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 10% in September, the driest month, to 18% in December, the wettest. Winds in Ontario are highest in February, averaging 4.1 m/s (15 km/h), and lightest in July, at 2.7 m/s (10 km/h). The prevailing wind is from the W. The clearest skies in Ontario come in July, when the sky is typically 51% covered; January is the cloudiest month, at 81%.
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
-8°C
16%
81%
4.0 m/s
0
0
2
February
0°C
-2°C
-7°C
14%
75%
4.1 m/s
0
0
5
March
4°C
0°C
-2°C
13%
67%
4.1 m/s
2
0
14
April
9°C
5°C
4°C
16%
66%
3.8 m/s
11
1
35
May
16°C
11°C
13°C
13%
60%
3.0 m/s
39
8
65
June
21°C
17°C
20°C
11%
55%
3.0 m/s
67
24
61
July
25°C
20°C
25°C
11%
51%
2.7 m/s
66
52
31
August
24°C
19°C
24°C
11%
52%
2.8 m/s
71
47
37
September
21°C
15°C
20°C
10%
53%
2.8 m/s
69
21
66
October
15°C
10°C
11°C
16%
64%
3.3 m/s
31
3
63
November
7°C
4°C
1°C
15%
70%
3.8 m/s
5
0
21
December
2°C
-1°C
-4°C
18%
79%
3.9 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 January, its coolest month, and 25°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 10°C around the clock. Rain is most likely around December and least likely around September. 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 0°CLow -2°CRain 16%
Winter in Ontario has typical daily highs of about 0°C and lows of about -2°C, with a 16% chance of rain on a given day.
Ontario weather in springMarch to May
High 9°CLow 5°CRain 14%
Spring in Ontario has typical daily highs of about 9°C and lows of about 5°C, with a 14% chance of rain on a given day.
Ontario weather in summerJune to August
High 24°CLow 18°CRain 11%
Summer in Ontario has typical daily highs of about 24°C and lows of about 18°C, with a 11% chance of rain on a given day.
Ontario weather in autumnSeptember to November
High 14°CLow 10°CRain 14%
Autumn in Ontario has typical daily highs of about 14°C and lows of about 10°C, with a 14% 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 10% in September, the driest month, to 18% in December, the wettest.
What time of year is Ontario windiest?
Winds in Ontario are highest in February, averaging 4.1 m/s (15 km/h), and lightest in July, at 2.7 m/s (10 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 10°C. July is the hottest month, with highs of about 25°C; January is the coldest, with lows of about -3°C.