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Weather in Ontario, California for January 2026

Your guide to Ontario weather in January - trends and predictions

    Official Weather Alert ⚠️

  • Wind Advisory - See hour by hour.

    • Temperatures

  • Until now, January 2026 in Ontario has been nearly identical to the historical average, with a temperature of 16.6 °F (showing only a slight deviation of 0.4 °F).

  • Expect cooler weather in the next days in Ontario with the forecast suggesting a temperature of 23.2 °F, lower than the historical average.

  • In general, the average temperature in Ontario at the beginning of January is 15.1 °F. As the month progressed, temperatures tended to significantly warm up, reaching an average of 20.9 °F by the end of January.

    • Rain 🌧️

  • Ontario experiences moderate rainfall in January, with an average of 7 rainy days and a total precipitation of 47.9 mm.

    • More

  • New! Chat with our AI weatherman - it’s amazing and free.

Average dry days
24
Dry days
Average rainy days
7
Rainy days
Average snowy days
0
Snow days
Average temperatures
16°/7°
Temperatures
Average wind speed
11 km/h
Avg max wind
Average humidity
44 %
Avg humidity

Ontario Weather January

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

Temperatures trend during January in Ontario

See the weather trend as well as the moving average line

January weather in Ontario day by day

Click on a date for more information
December February
Date Weather Temperatures Rain UV More
Jan. 1 Partly cloudy
Partly cloudy
 17° /8° 74.8 mm 3
Jan. 2 Overcast
Overcast
 18° /8° 3.1 mm 3
Jan. 3 Light rain shower
Light rain shower
 14° /8° 10.3 mm 2
Jan. 4 Overcast
Overcast
 14° /5° 32.2 mm 3
Jan. 5 Partly cloudy
Partly cloudy
 15° /8° 12.2 mm 3
Jan. 6 Sunny
Sunny
 16° /8° 0 mm 3
Jan. 7 Patchy rain possible
Patchy rain possible
 12° /5° 0.7 mm 2
Jan. 8 Cloudy
Cloudy
 13° /5° 0.1 mm 3
Jan. 9 Sunny
Sunny
 16° /5° 0 mm 4
Jan. 10 Sunny
Sunny
 16° /5° 0 mm 3
Jan. 11 Sunny
Sunny
 17° /4° 0 mm 3
Jan. 12 Sunny
Sunny
 17° /5° 0 mm 4
Jan. 13 Sunny
Sunny
 17° /7° 0 mm 3
Jan. 14 Sunny
Sunny
 19° /9° 0 mm 4
Jan. 15 Sunny
Sunny
 19° /10° 0 mm 3
Jan. 16 Sunny
Sunny
 21° /8° 0 mm 4
Jan. 17 Partly cloudy
Partly cloudy
 16° /7° 0 mm 3
Jan. 18 Sunny
Sunny
 17° /6° 0 mm 5
Jan. 19 Sunny
Sunny
 20° /10° 0 mm 3
Jan. 20 Sunny
Sunny
 18° /7° 1.5 mm 3
Jan. 21 Overcast
Overcast
 14° /7° 3.7 mm 2
Jan. 22 Light rain shower
Light rain shower
 15° /9° 9.4 mm 3
Jan. 23 Patchy rain possible
Patchy rain possible
 15° /7° 0 mm 3
Jan. 24 Overcast
Overcast
 17° /7° 1.6 mm 4
Jan. 25 Overcast
Overcast
 15° /6° 0 mm 3
Jan. 26 Sunny
Sunny
 14° /5° 6.9 mm 3
Jan. 27 Sunny
Sunny
 17° /8° 6.5 mm 3
Jan. 28 Sunny
Sunny
 26° /10° 0 mm 0.6
Jan. 29 Sunny
Sunny
 24° /11° 0 mm 0.8
Jan. 30 Sunny
Sunny
 25° /12° 0 mm 0.9
Jan. 31 Sunny
Sunny
 25° /12° 0 mm 0.9
Next
Important Notice
Our weather forecast for Ontario in January 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.
Change Month
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Ontario in January - FAQ

What are the expected maximum and minimum temperatures in Ontario during January?

Enjoy moderate daytime temperatures of up to 16° and cooler nights around 7°. Ideal for a range of outdoor activities, from hiking to city tours.

How much rainfall should be expected in Ontario during January?

In January, Ontario can expect light to moderate rainfall, totaling 47.9 mm across approximately 7 days. Occasional showers are possible, and planning ahead for them could be helpful.

What are the typical wind conditions in Ontario during January?

The average wind speed in Ontario during January is 11 km/h, suggesting breezy to windy conditions, depending on your activities.

January rainfall patterns in Ontario

Explore the daily rainfall trends and prepare for Ontarios January weather 💧
Typically, Ontario has 7 rainy days in January with a total of 47.9 mm of rainfall.

UV exposure in Ontario during January

Stay informed about UV levels for safe outdoor activities throughout the month of January ☀️

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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