Search results
Get the monthly weather forecast for Ontario, CA, including daily high/low, historical averages, to help you plan ahead.
Check accurate weather in December in Ontario (CA). Expect Ontario December temperature around 19°C (65°F). Read clothing tips & recommended activities.
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).
Calculate distances between locations with MapQuest's distance calculator tool, providing accurate measurements for travel planning.
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.
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.
Ontario, California - Winter. December weather forecast. Average monthly weather with temperature, pressure, humidity, precipitation, wind, daylight, sunshine, visibility, and UV index data.
