ClimateForecastNovemberDecember >>

Ontario (CA) Climate by Month

The climate in Ontario is marked by big temperature swings throughout the year. Temperatures range from very warm during the warmest months to pleasant in the cooler months. The city tends toward drier weather patterns. Now, let’s explore all the climate details to give you a full picture.

Average day and night temperature

In Ontario, temperatures differ significantly between summer and winter months. Average daytime temperatures reach a very warm 34°C in August. In December, the coolest month of the year, temperatures drop to a pleasant 19°C. At night, expect cooler temperatures, averaging 6°C during this month.

The mean minimum and maximum temperatures throughout the year

Precipitation and rainy days

Ontario tends toward drier weather patterns, receiving approximately 273 mm of rain per year. Ontario can be quite wet during December, receiving approximately 78 mm of precipitation over 8 rainy days. In contrast June, experiences much drier conditions, with 0.1 mm of rainfall, spread across 0 rainy days.

The mean monthly precipitation over the year, including rain, hail and snow

Sunshine over the year

Ontario can be enjoyed more throughout the sunniest month of July under a blue sky, with approximately 12.3 hours of sunshine daily. In contrast, the city experiences much darker days in January, with only 6.6 hours of sunlight per day.

Monthly hours of sunshine

Data from: Corona, the United States of America (22 KM, 13 Miles).

Daily hours of sunshine

Data from: Corona, the United States of America (22 KM, 13 Miles).

The best time of year to visit Ontario in the United States of America

During the months of January, February, March, April, May and November you are most likely to experience good weather with pleasant average temperatures that fall between 20°C and 26°C.

Other facts from our historical weather data:
  • Which is the warmest month in Ontario?
    August has an average maximum temperature of 34°C and is the warmest month of the year.
  • Which is the coldest month in Ontario?
    The coldest month is December with an average maximum temperature of 19°C.
  • Which is the wettest month in Ontario?
    December tops the wettest month list with 78 mm of rainfall.
  • Which is the driest month in Ontario?
    June is the driest month with 0 mm of precipitation.
  • Which is the sunniest month in Ontario?
    July is the sunniest month with an average of 369 hours of sunshine.

  • No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.

    Forecast for Ontario (CA)

    Sat   Nov 23
    18°C | 9°C
    W 11 km/h
    2.8 mm
    broken clouds and rain

    broken clouds and rain

    Sun   Nov 24
    19°C | 11°C
    W 14 km/h
    1.5 mm
    partly cloudy and small chance of slight rain

    partly cloudy and small chance of slight rain

    Mon   Nov 25
    21°C | 10°C
    W 7 km/h
    broken clouds and no rain

    broken clouds and no rain