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Get the monthly weather forecast for Ontario, CA, including daily high/low, historical averages, to help you plan ahead.
The lowest daily average low temperature is 44°F on December 25. For reference, on August 21, the hottest day of the year, temperatures in Ontario typically range from 66°F to 93°F, while on December 24, the coldest day of the year, they range from 44°F to 66°F.
The weather in Ontario in December is moderately chilly with a gentle breeze, with average highs of 64°F (18°C) and lows of 43°F (6°C).
Check accurate weather in December in Ontario (CA). Expect Ontario December temperature around 19°C (65°F). Read clothing tips & recommended activities.
We show the December climate in California by comparing the average December weather in 5 representative places: Los Angeles, San Francisco, Sacramento, Palm Springs, and Eureka. You can add or remove cities to customize the report to your liking.
With the distance calculator distance.to you can easily determine distances between world-wide locations. Simply enter any desired location into the search function and you will get the shortest distance (air line) between the points, the route (route planner) as well as all important information.
Ontario, California - Winter. December weather forecast. Average monthly weather with temperature, pressure, humidity, precipitation, wind, daylight, sunshine, visibility, and UV index data.
