December weather forecast
Forestville, CA

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Weather in December

The first month of the winter, December, is still a mild month in Forestville, California, with an average temperature varying between 55.8°F (13.2°C) and 40.5°F (4.7°C).

Temperature

December, on average, is the coldest month, registering a high temperature of 55.8°F (13.2°C) and a low of 40.5°F (4.7°C).

Humidity

In December, the average relative humidity in Forestville is 74%.

Rainfall

In Forestville, in December, it is raining for 11.6 days, with typically 3.27" (83mm) of accumulated precipitation. Throughout the year, there are 80.5 rainfall days, and 17.6" (447mm) of precipitation is accumulated.

Daylight

The month with the shortest days in Forestville is December, 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

December has the least sunshine of the year, with an average of 5.6h 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 of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: The UV index of 3 in December translates into these instructions:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Updated: Jun 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest month?

December is the coldest month, with an average high-temperature of 55.8°F (13.2°C) and an average low-temperature of 40.5°F (4.7°C).

What is the average December temperature?

The average high-temperature, in December, in Forestville, is 55.8°F (13.2°C), while the average low-temperature is 40.5°F (4.7°C). In September, the average heat index (a.k.a. 'real feel', 'feels like'), which combines air temperature and relative humidity, is computed to be 84.2°F (29°C).

What is the average humidity in December?

In Forestville, the average relative humidity in December is 74%.

How many days does it rain in December?

In Forestville, in December, it is raining for 11.6 days, with typically 3.27" (83mm) of accumulated precipitation.

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.

How many hours of daylight does Forestville have in December?

The average day length in December is 9h and 32min.

When is the sunrise / sunset in December?

In December, on the first day of the month, 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 in Forestville?

With an average of 5.6h of sunshine, December has the least sunshine of the year.

How long on average sun shines in December?

In December, the average sunshine duration is 5.6h.

When is the lowest UV index?

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

What is the UV index intensity in December?

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

Average temperature in December
Forestville, CA

Average temperature in December - Forestville, CA
  • Average high temperature in December: 55.8°F

The warmest month (with the highest average high temperature) is August (83.5°F).
The month with the lowest average high temperature is December (55.8°F).

  • Average low temperature in December: 40.5°F

The month with the highest average low temperature is August (54.3°F).
The coldest month (with the lowest average low temperature) is December (40.5°F).

Average pressure in December
Forestville, CA

Average pressure in December - Forestville, 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
Forestville, CA

Average wind speed in December - Forestville, CA
  • Average wind speed in December: 4.8mph

The windiest month (with the highest average wind speed) is May (6.4mph).
The calmest month (with the lowest average wind speed) is November (4.5mph).

Average humidity in December
Forestville, CA

Average humidity in December - Forestville, CA
  • Average humidity in December: 74%

The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (58%).

Average rainfall in December
Forestville, CA

Average rainfall in December - Forestville, CA
  • Average rainfall in December: 3.27"

The wettest month (with the highest rainfall) is February (3.78").
The driest months (with the least rainfall) are July and August (0.04").

Average rainfall days in December
Forestville, CA

Average rainfall days in December - Forestville, CA
  • Average rainfall days in December: 11.6 days

The month with the highest number of rainy days is March (14.3 days).
The month with the least rainy days is July (1 days).

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

Average daylight in December / Average sunshine in December - Forestville, 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: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 36min).

Average sunshine days in December
Forestville, CA

Average sunshine days in December - Forestville, CA
  • Average sunshine days in December: 18.5 days

The month with the most sunshine days is July (29.1 days).
The month with the least sunshine days is March (15.3 days).

Average UV index in December
Forestville, CA

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

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

Average cloud cover in December
Forestville, CA

Average cloud cover in December - Forestville, CA
  • Average cloud cover in December: 38

The month with the most cloud cover is March (Cloud cover 41).
The month with the least cloud cover is July (Cloud cover 8).

Average visibility in December
Forestville, CA

Average visibility in December - Forestville, 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).

Forestville, California, USA

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