December weather forecast
Sierra Heights, CA

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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.
Updated: Jun 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the coldest months?

Sierra Heights's coldest month, December, registers temperatures that range from a high of 60.8°F (16°C) to a low of 44.2°F (6.8°C).

What is the usual temperature for Sierra Heights in December?

The high-temperature during December is 60.8°F (16°C) and the low-temperature is 44.2°F (6.8°C). The average heat index (a.k.a. 'feels like', 'apparent temperature'), which represents the influence of relative humidity on air temperature, in September is computed to be 89.6°F (32°C).

What is the average humidity in December?

In December, the average relative humidity is 51%.

How much does it rain in December?

In Sierra Heights, during December, the rain falls for 5.9 days and regularly aggregates up to 1.5" (38mm) of precipitation.

When it does not snow?

In Sierra Heights, snow does not fall in January, March through December.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 9h and 54min of daylight.

What is the average length of the day in December?

In December, the average day length is 9h and 55min.

When is the sunrise / sunset in December?

In December, on the first day of the month, 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.

What is the month with the least sunshine?

December has the least sunshine of the year, with an average of 6.9h of sunshine.

How long on average sun shines in December?

The average sunshine duration in December is 6.9h.

When is the lowest UV index?

With an average maximum UV index of 3, December is the month with the lowest UV index.

What is the UV index reading in December?

The average daily maximum UV index in December is 3. A UV Index of 3 to 5 symbolizes a medium hazard to health from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Sierra Heights, CA

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 - 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 - 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 - 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 - 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 - 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 - 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 / Average sunshine in December - Sierra Heights, CA
  • Average daylight in December: 9h and 5min

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 5min

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 - 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 - 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 - 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 - 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).

Sierra Heights, California, USA

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