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Weather in Ontario, California for December 2026

Your guide to Ontario weather in December - trends and predictions

    Temperatures

  • In general, the average temperature in Ontario at the beginning of December is 20.7 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 15.7 °C by the end of December.

    • Rain 🌧️

  • With an average of 4 rainy days, Ontario experiences minimal rainfall in December.

    • More

  • Is December a good time to visit Ontario? check out the best time to travel to Ontario page.

  • ✨ Is December a good time to visit Ontario? – Ask the AI Weatherman

Average dry days
27
Dry days
Average rainy days
4
Rainy days
Average snowy days
0
Snow days
Average temperatures
19°/10°
Temperatures
Average wind speed
9 km/h
Avg max wind
Average humidity
45 %
Avg humidity

Ontario Weather December

Move between months or click on a day
November
January
Sun.Mon.Tue.Wed.Thu.Fri.Sat.
1
Sunny
20°
2
Sunny
19°
3
Sunny
19°
4
Overcast
21°
5
Sunny
23°
6
Sunny
22°
7
Partly cloudy
21°
8
Sunny
21°
9
Sunny
21°
10
Sunny
23°
11
Overcast
22°
12
Sunny
18°
13
Sunny
18°
14
Overcast
20°
15
Partly cloudy
22°
16
Sunny
23°
17
Partly cloudy
23°
18
Sunny
23°
19
Light rain
20°
20
Light rain
19°
21
Patchy light rain with thunder
18°
22
Patchy rain possible
18°
23
Patchy rain possible
17°
24
Heavy rain
15°
25
Light rain
16°
26
Heavy rain
14°
27
Overcast
14°
28
Cloudy
18°
29
Sunny
18°
30
Light rain
15°
31
Moderate rain
16°

Temperatures trend during December in Ontario

See the weather trend as well as the moving average line

December weather in Ontario day by day

Click on a date for more information
November January
Date Weather Temperatures Rain UV More
Dec. 1 Sunny
Sunny
 20° /10° 0 mm 3
Dec. 2 Sunny
Sunny
 19° /9° 0 mm 3
Dec. 3 Sunny
Sunny
 19° /9° 0 mm 3
Dec. 4 Overcast
Overcast
 21° /10° 0 mm 3
Dec. 5 Sunny
Sunny
 23° /10° 0 mm 2.9
Dec. 6 Sunny
Sunny
 22° /11° 0 mm 2.9
Dec. 7 Partly cloudy
Partly cloudy
 21° /10° 0 mm 2.9
Dec. 8 Sunny
Sunny
 21° /11° 0 mm 2.9
Dec. 9 Sunny
Sunny
 21° /9° 0 mm 2.9
Dec. 10 Sunny
Sunny
 23° /10° 0 mm 2.9
Dec. 11 Overcast
Overcast
 22° /10° 0 mm 2.8
Dec. 12 Sunny
Sunny
 18° /9° 0 mm 2.8
Dec. 13 Sunny
Sunny
 18° /9° 0 mm 2.8
Dec. 14 Overcast
Overcast
 20° /11° 0 mm 2.8
Dec. 15 Partly cloudy
Partly cloudy
 22° /8° 0 mm 2.8
Dec. 16 Sunny
Sunny
 23° /13° 0 mm 2.8
Dec. 17 Partly cloudy
Partly cloudy
 23° /11° 0 mm 2.8
Dec. 18 Sunny
Sunny
 23° /14° 0.2 mm 2.8
Dec. 19 Light rain
Light rain
 20° /11° 2.9 mm 2.8
Dec. 20 Light rain
Light rain
 19° /12° 3.6 mm 2.8
Dec. 21 Patchy light rain with thunder
Patchy light rain with thunder
 18° /10° 2.2 mm 2.8
Dec. 22 Patchy rain possible
Patchy rain possible
 18° /12° 2.1 mm 2.8
Dec. 23 Patchy rain possible
Patchy rain possible
 17° /10° 1.1 mm 2.8
Dec. 24 Heavy rain
Heavy rain
 15° /10° 103.4 mm 2.8
Dec. 25 Light rain
Light rain
 16° /9° 3.2 mm 2.8
Dec. 26 Heavy rain
Heavy rain
 14° /9° 48.2 mm 2.8
Dec. 27 Overcast
Overcast
 14° /8° 0 mm 2.8
Dec. 28 Cloudy
Cloudy
 18° /8° 0 mm 2.8
Dec. 29 Sunny
Sunny
 18° /8° 0 mm 2.8
Dec. 30 Light rain
Light rain
 15° /7° 3.2 mm 2.8
Dec. 31 Moderate rain
Moderate rain
 16° /8° 17.8 mm 2
Next
Important Notice
Our weather forecast for Ontario in December is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Ontario forecast closer to your planned date for the most up-to-date weather information.
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Ontario in December - FAQ

What are the expected maximum and minimum temperatures in Ontario during December?
Enjoy moderate daytime temperatures of up to 19° and cooler nights around 10°. Ideal for a range of outdoor activities, from hiking to city tours.

How much rainfall should be expected in Ontario during December?
Significant rainfall exceeding 188 mm is expected in Ontario during December, occurring over more than 4 days. Preparing for wet conditions is recommended in your planning.

What are the typical wind conditions in Ontario during December?
The average wind speed in Ontario during December is 9 km/h, suggesting breezy to windy conditions, depending on your activities.

December rainfall patterns in Ontario

Explore the daily rainfall trends and prepare for Ontarios December weather 💧
Typically, Ontario has 4 rainy days in December with a total of 188 mm of rainfall.

UV exposure in Ontario during December

Stay informed about UV levels for safe outdoor activities throughout the month of December ☀️
Quick links
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Location coordinates Where is Ontario?

Get accurate weather forecasts for Ontario, located at latitude 34.063 and longitude -117.651. Stay updated with localized weather information tailored for Ontario.

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