December weather forecast
August, CA

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Weather in December

The first month of the winter, December, is also a fresh month in August, California, with an average temperature ranging between min 41.2°F (5.1°C) and max 55.2°F (12.9°C).

Temperature

August witnesses the coldest weather in December, with temperatures averaging a high of 55.2°F (12.9°C) and a low of 41.2°F (5.1°C).

Humidity

In August, the average relative humidity in December is 71%.

Rainfall

In December, the rain falls for 9 days. Throughout December, 1.77" (45mm) of precipitation is accumulated. Throughout the year, there are 64.2 rainfall days, and 11.34" (288mm) of precipitation is accumulated.

Snowfall

December is the only month when snow falls. December has the most snowfall days of the year. 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 the month, sunrise is at 7:02 am and sunset at 4:45 pm. On the last day of December, sunrise is at 7:20 am and sunset at 4:55 pm PST.

Sunshine

December has the least sunshine of the year, with an average of 5.9h of sunshine.

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 reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.
Note: A daily high UV index of 3 in December leads to these guidelines:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Updated: Aug 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the coldest months in August?

August's December weather reaches an average high of 55.2°F (12.9°C) and an average low of 41.2°F (5.1°C), making it the coldest month.

What are the temperatures in December?

The average high-temperature and low-temperature during December are 55.2°F (12.9°C) and 41.2°F (5.1°C) respectively. The average heat index (a.k.a. 'real feel', 'feels like'), which factors the actual air temperature with the relative humidity, in September is estimated at 91.4°F (33°C).

What is the average humidity in December?

The average relative humidity in December is 71%.

How many days does it rain in December?

In August, during December, the rain falls for 9 days and regularly aggregates up to 1.77" (45mm) of precipitation.

What is the snowiest month?

December has the most snowfall days of the year. Snow falls for 0.1 days.

When does it start to snow?

December is the first month it typically snows. Throughout December, there are 0.1 snowfall days.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 36min of daylight.

What is the average length of the day in December?

In December, the average day length is 9h and 35min.

When are sunrise and sunset in December in August?

In December, on the first day of the month, sunrise is at 7:02 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 4:55 pm PST.

What is the month with the least sunshine?

The month with the least sunshine is December, with an average of 5.9h of sunshine.

How many hours of sunshine does August have in December?

In December, the average sunshine duration is 5.9h.

What is the month with the lowest UV index?

January, February, November and December, with an average maximum UV index of 3, are months with the lowest UV index.

What is the UV index intensity in December?

In December, the average daily maximum UV index is 3. A UV Index reading of 3 to 5 represents a medium health risk from exposure to Sun's UV rays.
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
August, CA

Average temperature in December - August, CA
  • Average high temperature in December: 55.2°F

The warmest month (with the highest average high temperature) is July (94.3°F).
The month with the lowest average high temperature is December (55.2°F).

  • Average low temperature in December: 41.2°F

The month with the highest average low temperature is August (59.5°F).
The coldest month (with the lowest average low temperature) is December (41.2°F).

Average pressure in December
August, CA

Average pressure in December - August, CA
  • Average pressure in December: 30.12"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in December
August, CA

Average wind speed in December - August, CA
  • Average wind speed in December: 5.4mph

The windiest month (with the highest average wind speed) is June (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.7mph).

Average humidity in December
August, CA

Average humidity in December - August, CA
  • Average humidity in December: 71%

The month with the highest relative humidity is January (73%).
The month with the lowest relative humidity is July (44%).

Average rainfall in December
August, CA

Average rainfall in December - August, CA
  • Average rainfall in December: 1.77"

The wettest month (with the highest rainfall) is February (2.13").
The driest month (with the least rainfall) is August (0").

Average rainfall days in December
August, CA

Average rainfall days in December - August, CA
  • Average rainfall days in December: 9 days

The month with the highest number of rainy days is March (12 days).
The month with the least rainy days is August (0.7 days).

Average snowfall days in December
August, CA

Average snowfall days in December - August, 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
August, CA

Average daylight in December / Average sunshine in December - August, CA
  • Average daylight in December: 9h and 4min

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 5min

The month with the most sunshine is July (Average sunshine: 12h and 12min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).

Average sunshine days in December
August, CA

Average sunshine days in December - August, CA
  • Average sunshine days in December: 21.1 days

The month with the most sunshine days is August (30.2 days).
The month with the least sunshine days is March (17.8 days).

Average UV index in December
August, CA

Average UV index in December - August, CA
  • Average UV index in December: 3

The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).

Average cloud cover in December
August, CA

Average cloud cover in December - August, CA
  • Average cloud cover in December: 34

The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 4).

Average visibility in December
August, CA

Average visibility in December - August, 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).

August, California, USA

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