December weather forecastOakley, CA
December
Weather in December
The first month of the winter, December, is also a fresh month in Oakley, California, with an average temperature fluctuating between 41.7°F (5.4°C) and 55°F (12.8°C).Temperature
Oakley's December weather, with an average high temperature of 55°F (12.8°C) and an average low temperature of 41.7°F (5.4°C), tends to be the coldest of the year.Humidity
In Oakley, California, the average relative humidity in December is 71%.Rainfall
In Oakley, 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
The only month with snowfall is December. December has the most snowfall days of the year in Oakley. Snow falls for 0.1 days.Daylight
December has the shortest days of the year, with an average of 9h and 36min of daylight.On the first day of December in Oakley, 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
December has the least sunshine of the year in Oakley, California, with an average of 5.8h of sunshine.UV index
January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index in Oakley. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the average person.Note: A maximum daily UV index of 3 during December morphs into the following directions:
Make use of precautions - It is urged to ward off sun damage. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Attention! Nearly twice the Sun's UV radiation can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Oakley, 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
Oakley, 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
Oakley, 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
Oakley, 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
Oakley, 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
Oakley, 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
Oakley, 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
Oakley, CA
- Average daylight in December: 9h and 36min
The month with the longest days is June (Average daylight: 14h and 48min).
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
Oakley, 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
Oakley, 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
Oakley, 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
Oakley, 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).
