December weather forecastWestley, CA
December
Weather in December
December, the first month of the winter in Westley, is still a mild month, with an average temperature varying between 55.4°F (13°C) and 41°F (5°C).Temperature
December is the coldest month, with an average high-temperature of 55.4°F (13°C) and an average low-temperature of 41°F (5°C).Humidity
The average relative humidity in December is 71%.Rainfall
The wettest months are March and December, with an average 0.47" (12mm) of rainfall.Daylight
The month with the shortest days is December, with an average of 9h and 36min of daylight.On the first day of December, sunrise is at 7:01 am and sunset at 4:46 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:56 pm PST.
Sunshine
With an average of 6h of sunshine, December has the least sunshine of the year.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 3. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 3 during December translates into these guidelines:
Ensure safety - Sun damage prevention is strongly urged. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Westley, CA
- Average high temperature in December: 55.4°F
The warmest month (with the highest average high temperature) is July (96.4°F).
The month with the lowest average high temperature is December (55.4°F).
- Average low temperature in December: 41°F
The months with the highest average low temperature are July and August (60.8°F).
The coldest months (with the lowest average low temperature) are January and December (41°F).
Average pressure in December
Westley, CA
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Westley, CA
- Average wind speed in December: 5.5mph
The windiest month (with the highest average wind speed) is June (6.7mph).
The calmest months (with the lowest average wind speed) are January and November (5.1mph).
Average humidity in December
Westley, CA
- Average humidity in December: 71%
The month with the highest relative humidity is January (72%).
The month with the lowest relative humidity is July (39%).
Average rainfall in December
Westley, CA
- Average rainfall in December: 0.47"
The wettest months (with the highest rainfall) are March and December (0.47").
The driest months (with the least rainfall) are June and August (0.04").
Average rainfall days in December
Westley, CA
- Average rainfall days in December: 6.9 days
The month with the highest number of rainy days is March (8.5 days).
The month with the least rainy days is June (1 days).
Average daylight in December /
Average sunshine in December
Westley, CA
- Average daylight in December: 9h and 36min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in December: 6h and 0min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 0min).
Average sunshine days in December
Westley, CA
- Average sunshine days in December: 22.8 days
The month with the most sunshine days is August (28.9 days).
The month with the least sunshine days is March (20.9 days).
Average UV index in December
Westley, CA
- Average UV index in December: 3
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in December
Westley, CA
- Average cloud cover in December: 33
The month with the most cloud cover is March (Cloud cover 34).
The month with the least cloud cover is July (Cloud cover 4).
Average visibility in December
Westley, CA
- Average visibility in December: 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).
