December weather forecastPlacentia, CA
December
Weather in December
December, the first month of the winter in Placentia, is still a comfortable month, with an average temperature fluctuating between 50.2°F (10.1°C) and 64.2°F (17.9°C).Temperature
With average high and low temperatures of 64.2°F (17.9°C) and 50.2°F (10.1°C) respectively, December is Placentia's coldest month.Humidity
In December, the average relative humidity in Placentia is 54%.Rainfall
The month with the most rainfall is December, when the rain falls for 6.8 days and typically aggregates up to 1.65" (42mm) of precipitation.Daylight
December has the shortest days of the year, with an average of 9h and 54min of daylight.On the first day of the month, sunrise is at 6:39 am and sunset at 4:42 pm. On the last day of December, sunrise is at 6:56 am and sunset at 4:53 pm PST.
Sunshine
February and December, with an average of 6.8h of sunshine, are months with the least sunshine.UV index
January, February, November and December, with an average maximum UV index of 4, are months with the lowest UV index. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for the average person.Note: A daily maximum UV index of 4 in December translates into the following instructions:
Guard yourself - Avoiding sunburn is suggested. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Placentia, CA
- Average high temperature in December: 64.2°F
The warmest month (with the highest average high temperature) is August (85.3°F).
The month with the lowest average high temperature is December (64.2°F).
- Average low temperature in December: 50.2°F
The month with the highest average low temperature is August (65.7°F).
The coldest month (with the lowest average low temperature) is February (49.6°F).
Average pressure in December
Placentia, CA
- Average pressure in December: 30.07"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in December
Placentia, CA
- Average wind speed in December: 5mph
The windiest month (with the highest average wind speed) is April (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity in December
Placentia, CA
- Average humidity in December: 54%
The month with the highest relative humidity is June (63%).
The month with the lowest relative humidity is November (50%).
Average rainfall in December
Placentia, CA
- Average rainfall in December: 1.65"
The wettest month (with the highest rainfall) is December (1.65").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in December
Placentia, CA
- Average rainfall days in December: 6.8 days
The month with the highest number of rainy days is March (7.4 days).
The month with the least rainy days is June (1.4 days).
Average daylight in December /
Average sunshine in December
Placentia, CA
- Average daylight in December: 9h and 54min
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 December: 6h and 48min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 48min).
Average sunshine days in December
Placentia, CA
- Average sunshine days in December: 23.4 days
The month with the most sunshine days is August (26.7 days).
The month with the least sunshine days is February (20.7 days).
Average UV index in December
Placentia, CA
- Average UV index in December: 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 December
Placentia, CA
- Average cloud cover in December: 22
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 5).
Average visibility in December
Placentia, 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).
