December weather forecast
Graton, CA

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Weather in December

December, the first month of the winter in Graton, is still a mild month, with an average temperature ranging between max 55.6°F (13.1°C) and min 41.9°F (5.5°C).

Temperature

Graton reaches its lowest average temperatures in December, measuring 55.6°F (13.1°C) at the peak and 41.9°F (5.5°C) at the lowest.

Humidity

In Graton, the average relative humidity in December is 75%.

Rainfall

In December, in Graton, the rain falls for 10.5 days. Throughout December, 2.24" (57mm) of precipitation is accumulated. In Graton, during the entire year, the rain falls for 72.8 days and collects up to 12.01" (305mm) of precipitation.

Daylight

December has the shortest days of the year, with an average of 9h and 30min of daylight.
On the first day of December, sunrise is at 7:10 am and sunset at 4:51 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 5:01 pm PST.

Sunshine

The month with the least sunshine in Graton is December, with an average of 5.7h 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 value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the average person.
Note: An average UV index of 3 in December transforms into this advice:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Updated: Aug 11, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the coldest?

December, known for its average high temperature of 55.6°F (13.1°C) and an average low temperature of 41.9°F (5.5°C), is the coldest month.

What is the usual temperature for Graton in December?

The average high-temperature, in December, in Graton, is 55.6°F (13.1°C), while the average low-temperature is 41.9°F (5.5°C).

What is the average humidity in December?

The average relative humidity in December is 75%.

How much does it rain in December?

In December, the rain falls for 10.5 days. Throughout December, 2.24" (57mm) of precipitation is accumulated.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 30min of daylight.

What is the average length of the day in December?

In December, the average day length is 9h and 32min.

What time are sunrise and sunset in December?

On the first day of December, sunrise is at 7:10 am and sunset at 4:51 pm. On the last day of the month, sunrise is at 7:28 am and sunset at 5:01 pm PST.

What is the month with the least sunshine?

The month with the least sunshine is December, with an average of 5.7h of sunshine.

How long on average sun shines in December?

In December, the average sunshine duration is 5.7h.

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?

The average daily maximum UV index in December is 3. A UV Index reading of 3 to 5 represents a medium hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Graton, CA

Average temperature in December - Graton, CA
  • Average high temperature in December: 55.6°F

The warmest month (with the highest average high temperature) is August (79.7°F).
The month with the lowest average high temperature is December (55.6°F).

  • Average low temperature in December: 41.9°F

The months with the highest average low temperature are August and September (54.7°F).
The coldest month (with the lowest average low temperature) is December (41.9°F).

Average pressure in December
Graton, CA

Average pressure in December - Graton, CA
  • Average pressure in December: 30.1"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).

Average wind speed in December
Graton, CA

Average wind speed in December - Graton, CA
  • Average wind speed in December: 5.2mph

The windiest month (with the highest average wind speed) is May (7.1mph).
The calmest month (with the lowest average wind speed) is November (4.9mph).

Average humidity in December
Graton, CA

Average humidity in December - Graton, CA
  • Average humidity in December: 75%

The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is September (63%).

Average rainfall in December
Graton, CA

Average rainfall in December - Graton, CA
  • Average rainfall in December: 2.24"

The wettest month (with the highest rainfall) is February (2.64").
The driest months (with the least rainfall) are July and August (0.04").

Average rainfall days in December
Graton, CA

Average rainfall days in December - Graton, CA
  • Average rainfall days in December: 10.5 days

The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is August (0.8 days).

Average daylight in December /
Average sunshine in December
Graton, CA

Average daylight in December / Average sunshine in December - Graton, CA
  • Average daylight in December: 9h and 3min

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 30min).

  • Average sunshine in December: 5h and 4min

The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).

Average sunshine days in December
Graton, CA

Average sunshine days in December - Graton, CA
  • Average sunshine days in December: 19.5 days

The month with the most sunshine days is July (27.2 days).
The month with the least sunshine days is March (17.1 days).

Average UV index in December
Graton, CA

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

The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).

Average cloud cover in December
Graton, CA

Average cloud cover in December - Graton, CA
  • Average cloud cover in December: 37

The month with the most cloud cover is March (Cloud cover 39).
The month with the least cloud cover is July (Cloud cover 9).

Average visibility in December
Graton, CA

Average visibility in December - Graton, 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).

Graton, California, USA

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