January weather forecastWillowbrook, CA
January
Weather in January
January, like December, in Willowbrook, California, is another comfortable winter month, with temperature in the range of an average high of 65.8°F (18.8°C) and an average low of 52.2°F (11.2°C).Temperature
As Willowbrook welcomes January, the average high-temperature stabilizes at a still enjoyable 65.8°F (18.8°C), showing little deviation from December's 64°F (17.8°C). Willowbrook experiences an average low-temperature of 52.2°F (11.2°C) in the month of January.Humidity
The average relative humidity in January is 56%.Rainfall
The wettest months are January and February, with an average 1.26" (32mm) of rainfall.Daylight
In Willowbrook, the average length of the day in January is 10h and 12min.On the first day of the month, sunrise is at 6:58 am and sunset at 4:54 pm. On the last day of January, sunrise is at 6:50 am and sunset at 5:22 pm PST.
Sunshine
In Willowbrook, the average sunshine in January is 6.8h.UV index
The months with the lowest UV index in Willowbrook are January, February, November and December, with an average maximum UV index of 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 4 during January leads to these advisories:
Take measures. Individuals with light skin might experience burns in under 30 minutes. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Willowbrook, CA
- Average high temperature in January: 65.8°F
The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (64°F).
- Average low temperature in January: 52.2°F
The month with the highest average low temperature is August (65.1°F).
The coldest month (with the lowest average low temperature) is February (51.4°F).
Average pressure in January
Willowbrook, CA
- Average pressure in January: 30.1"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are June and September (29.89"Hg).
Average wind speed in January
Willowbrook, CA
- Average wind speed in January: 5.3mph
The windiest month (with the highest average wind speed) is April (6.3mph).
The calmest months (with the lowest average wind speed) are September and October (4.8mph).
Average humidity in January
Willowbrook, CA
- Average humidity in January: 56%
The month with the highest relative humidity is June (69%).
The month with the lowest relative humidity is November (53%).
Average rainfall in January
Willowbrook, CA
- Average rainfall in January: 1.26"
The wettest months (with the highest rainfall) are January and February (1.26").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in January
Willowbrook, CA
- Average rainfall days in January: 4.7 days
The month with the highest number of rainy days is March (7 days).
The month with the least rainy days is June (1.3 days).
Average daylight in January /
Average sunshine in January
Willowbrook, CA
- Average daylight in January: 10h and 12min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in January: 6h and 48min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in January
Willowbrook, CA
- Average sunshine days in January: 24.8 days
The month with the most sunshine days is August (25.3 days).
The month with the least sunshine days is February (21.1 days).
Average UV index in January
Willowbrook, CA
- Average UV index in January: 4
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 4).
Average cloud cover in January
Willowbrook, CA
- Average cloud cover in January: 21
The months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in January
Willowbrook, CA
- Average visibility in January: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





