December weather forecastDiablo, CA
December
Weather in December
The first month of the winter, December, is still a refreshing month in Diablo, California, with an average temperature ranging between min 42.3°F (5.7°C) and max 55.8°F (13.2°C).Temperature
December is the coldest month of the year, registering average temperatures as high as 55.8°F (13.2°C) and as low as 42.3°F (5.7°C).Humidity
In Diablo, the average relative humidity in December is 71%.Rainfall
In Diablo, in December, it is raining for 9.8 days, with typically 1.73" (44mm) of accumulated precipitation. Throughout the year, there are 65.6 rainfall days, and 11.22" (285mm) of precipitation is accumulated.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 7:05 am and sunset at 4:49 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 4:59 pm PST.
Sunshine
With an average of 5.8h of sunshine, December has the least sunshine of the year.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 moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: The maximum daily UV index of 3 in December converts into the following recommendations:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Diablo, CA
- Average high temperature in December: 55.8°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is December (55.8°F).
- Average low temperature in December: 42.3°F
The months with the highest average low temperature are August and September (56.7°F).
The coldest month (with the lowest average low temperature) is January (42.1°F).
Average pressure in December
Diablo, CA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in December
Diablo, CA
- Average wind speed in December: 4.8mph
The windiest month (with the highest average wind speed) is May (6.9mph).
The calmest month (with the lowest average wind speed) is November (4.3mph).
Average humidity in December
Diablo, CA
- Average humidity in December: 71%
The month with the highest relative humidity is March (74%).
The month with the lowest relative humidity is September (57%).
Average rainfall in December
Diablo, CA
- Average rainfall in December: 1.73"
The wettest month (with the highest rainfall) is February (2.36").
The driest months (with the least rainfall) are July and August (0").
Average rainfall days in December
Diablo, CA
- Average rainfall days in December: 9.8 days
The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is August (0.6 days).
Average daylight in December /
Average sunshine in December
Diablo, 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
Diablo, CA
- Average sunshine days in December: 20.6 days
The month with the most sunshine days is July (30.2 days).
The month with the least sunshine days is March (17.6 days).
Average UV index in December
Diablo, 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
Diablo, CA
- Average cloud cover in December: 35
The month with the most cloud cover is March (Cloud cover 36).
The month with the least cloud cover is July (Cloud cover 6).
Average visibility in December
Diablo, 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).
