December weather forecastSierra Heights, CA
December
Weather in December
The first month of the winter, December, is still a comfortable month in Sierra Heights, California, with an average temperature fluctuating between 44.2°F (6.8°C) and 60.8°F (16°C).Temperature
Sierra Heights's coldest weather arrives in December, when temperatures average a high of 60.8°F (16°C) and a low of 44.2°F (6.8°C).Humidity
In December, the average relative humidity is 51%.Rainfall
In Sierra Heights, during December, the rain falls for 5.9 days and regularly aggregates up to 1.5" (38mm) of precipitation. In Sierra Heights, during the entire year, the rain falls for 48.1 days and collects up to 6.89" (175mm) of precipitation.Snowfall
In Sierra Heights, snow does not fall in January, March through December.Daylight
December has the shortest days of the year, with an average of 9h and 54min of daylight.On the first day of December, sunrise is at 6:38 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 4:50 pm PST.
Sunshine
The month with the least sunshine is December, with an average of 6.9h of sunshine.UV index
The month with the lowest UV index is December, with an average maximum UV index of 3. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for the average person.Note: In December, the maximum UV index of 3 suggests this advice:
Undertake protective steps - Preventing sun damage is advised. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Sierra Heights, CA
- Average high temperature in December: 60.8°F
The warmest month (with the highest average high temperature) is August (92.1°F).
The month with the lowest average high temperature is December (60.8°F).
- Average low temperature in December: 44.2°F
The month with the highest average low temperature is August (67.3°F).
The coldest months (with the lowest average low temperature) are February and December (44.2°F).
Average pressure in December
Sierra Heights, 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 (29.85"Hg).
Average wind speed in December
Sierra Heights, CA
- Average wind speed in December: 5.3mph
The windiest months (with the highest average wind speed) are April and May (6mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity in December
Sierra Heights, CA
- Average humidity in December: 51%
The months with the highest relative humidity are February, March and May (52%).
The month with the lowest relative humidity is August (39%).
Average rainfall in December
Sierra Heights, CA
- Average rainfall in December: 1.5"
The wettest month (with the highest rainfall) is February (1.57").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in December
Sierra Heights, CA
- Average rainfall days in December: 5.9 days
The month with the highest number of rainy days is March (7.5 days).
The month with the least rainy days is June (1.2 days).
Average snowfall days in December
Sierra Heights, CA
- Average snowfall days in December: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in December /
Average sunshine in December
Sierra Heights, 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 54min
The months with the most sunshine are June, July and August (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 54min).
Average sunshine days in December
Sierra Heights, CA
- Average sunshine days in December: 23.8 days
The month with the most sunshine days is June (28.3 days).
The month with the least sunshine days is February (21.1 days).
Average UV index in December
Sierra Heights, CA
- Average UV index in December: 3
The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in December
Sierra Heights, CA
- Average cloud cover in December: 21
The months with the most cloud cover are February, March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 4).
Average visibility in December
Sierra Heights, 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).





