December weather forecast and climate
Graton, CA

Weather in December

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

Temperature

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

Humidity

In December, the average relative humidity is 75%.

Rainfall

In December, in Graton, the rain falls for 10.5 days. Throughout December, 2.24" (57mm) of precipitation is accumulated. Throughout the year, in Graton, there are 72.8 rainfall days, and 12.01" (305mm) of precipitation is accumulated.

Daylight

The month with the shortest days in Graton, California, is December, with an average of 9.5h of daylight.

Sunshine

With an average of 5.7h of sunshine, December has the least sunshine of the year in Graton.

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 the Sun's UV rays for the average person.
Note: The daily maximum UV index of 3 interpret into the following advice:
Take precautions - Protection against the skin and eye damage is obliged. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
[Resources]

FAQ

What is the coldest month in Graton?

December is the coldest month in Graton, California, with an average high-temperature of 55.6°F (13.1°C) and an average low-temperature of 41.9°F (5.5°C).

What is the temperature in December in Graton?

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

What is the average humidity in December in Graton?

In December, the average relative humidity is 75%.

How much does it rain in Graton 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 in Graton?

The month with the shortest days is December, with an average of 9.5h of daylight.

How many hours of daylight does Graton have in December?

In December, the average length of the day in Graton is 9.5h.

What is the month with the least sunshine in Graton?

December has the least sunshine of the year, with an average of 5.7h of sunshine.

How many hours of sunshine does Graton have in December?

The average sunshine in December in Graton is 5.7h.

When is the lowest UV index in Graton?

Months with the lowest UV index in Graton, California, are January, February, November and December, with an average maximum UV index of 3.

What is the UV index intensity in December in Graton?

The average daily maximum UV index in December in Graton, California, is 3. A UV Index value of 3 to 5 symbolizes a medium hazard to health from the exposure to the Sun's UV rays.

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

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).

[Resources]

Average pressure in December
Graton, CA

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

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

[Resources]

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).

[Resources]

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%).

[Resources]

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").

[Resources]

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).

[Resources]

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

Average daylight in December / Average sunshine in December - Graton, CA
  • Average daylight in December: 9.5h

The month with the longest days is June (Average daylight: 14.8h).
The month with the shortest days is December (Average daylight: 9.5h).

  • Average sunshine in December: 5.7h

The month with the most sunshine is July (Average sunshine: 11.9h).
The month with the least sunshine is December (Average sunshine: 5.7h).

[Resources]

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).

[Resources]

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).
Months with the lowest UV index are January, February, November and December (UV index 3).

[Resources]

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).

[Resources]

Average visibility in December
Graton, CA

Average visibility in December - Graton, CA
  • Average visibility in December: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

[Resources]