December weather forecastByron, CA
December
Weather in December
December, the first month of the winter in Byron, is still a cool month, with an average temperature ranging between max 55°F (12.8°C) and min 41.7°F (5.4°C).Temperature
December is the month that records the lowest temperatures, with averages ranging from a high of 55°F (12.8°C) to a low of 41.7°F (5.4°C).Humidity
In Byron, the average relative humidity in December is 71%.Rainfall
In Byron, in December, during 9.3 rainfall days, 1.57" (40mm) of precipitation is typically accumulated. Throughout the year, there are 62 rainfall days, and 10.16" (258mm) of precipitation is accumulated.Snowfall
December is the only month when snow falls. The month with the most snowfall days is December, when snow falls for 0.1 days.Daylight
With an average of 9h and 36min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:04 am and sunset at 4:47 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:57 pm PST.
Sunshine
With an average of 5.8h of sunshine, December has the least sunshine of the year in Byron.UV index
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the average person.Note: The daily high UV index of 3 during December translates into the following recommendations:
Take necessary precautions - Protection from skin and eye injury is mandatory. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes. Mind you! Snow reflection can increase the intensity of the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Byron, CA
- Average high temperature in December: 55°F
The warmest month (with the highest average high temperature) is July (88.5°F).
The month with the lowest average high temperature is December (55°F).
- Average low temperature in December: 41.7°F
The month with the highest average low temperature is September (57.7°F).
The coldest month (with the lowest average low temperature) is January (41.5°F).
Average pressure in December
Byron, CA
- Average pressure in December: 30.11"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
Byron, CA
- Average wind speed in December: 5mph
The windiest month (with the highest average wind speed) is June (7.8mph).
The calmest months (with the lowest average wind speed) are January and November (4.5mph).
Average humidity in December
Byron, CA
- Average humidity in December: 71%
The month with the highest relative humidity is January (74%).
The month with the lowest relative humidity is September (52%).
Average rainfall in December
Byron, CA
- Average rainfall in December: 1.57"
The wettest month (with the highest rainfall) is February (2.09").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in December
Byron, CA
- Average rainfall days in December: 9.3 days
The month with the highest number of rainy days is March (12.3 days).
The month with the least rainy days is August (0.8 days).
Average snowfall days in December
Byron, CA
- Average snowfall days in December: 0.1 days
The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).
Average daylight in December /
Average sunshine in December
Byron, 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: 5h and 48min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in December
Byron, CA
- Average sunshine days in December: 21.1 days
The month with the most sunshine days is August (29.8 days).
The month with the least sunshine days is March (17.7 days).
Average UV index in December
Byron, CA
- Average UV index in December: 3
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in December
Byron, CA
- Average cloud cover in December: 35
The months with the most cloud cover are March and December (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 5).
Average visibility in December
Byron, 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).





