December weather forecastBoonville, CA

December

Weather in December

The first month of the winter, December, is still a cool month in Boonville, California, with an average temperature varying between 37.4°F (3°C) and 53.6°F (12°C).

Temperature

Boonville witnesses the coldest weather in December, with temperatures averaging a high of 53.6°F (12°C) and a low of 37.4°F (3°C).

Humidity

In Boonville, the average relative humidity in December is 76%.

Rainfall

The months with the most rainfall are February and December, with an average 3.11" (79mm) of precipitation.

Snowfall

January, March through December are months without snowfall.

Daylight

With an average of 9h and 30min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 7:14 am and sunset at 4:51 pm. On the last day of the month, sunrise is at 7:32 am and sunset at 5:01 pm PST.

Sunshine

The month with the least sunshine is December, with an average of 5.3h of sunshine.

UV index

The average daily maximum UV index in December is 3. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the average person.
Note: In December, an average UV index of 3 transforms into the following instructions:
Prioritize safety - Suggestions to prevent sun damage are offered. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Updated: Jun 11, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

The coldest period is December, when temperatures fluctuate between an average high of 53.6°F (12°C) and a low of 37.4°F (3°C).

In December, in Boonville, the average high-temperature is 53.6°F (12°C), and the average low-temperature is 37.4°F (3°C). The average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, in September is appraised at 82.4°F (28°C).

In December, the average relative humidity is 76%.

The wettest months are February and December, with an average 3.11" (79mm) of rainfall.

In December, the rain falls for 12.5 days. Throughout December, 3.11" (79mm) of precipitation is accumulated.

January, March through December are months without snowfall.

December has the shortest days of the year in Boonville, with an average of 9h and 30min of daylight.

The average day length in December is 9h and 29min.

On the first day of December, sunrise is at 7:14 am and sunset at 4:51 pm. On the last day of the month, sunrise is at 7:32 am and sunset at 5:01 pm PST.

The month with the least sunshine is December, with an average of 5.3h of sunshine.

In Boonville, the average sunshine duration in December is 5.3h.

The average daily maximum UV index in December is 3. A UV Index estimate of 3 to 5 represents a medium health risk from exposure to Sun's UV rays.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Boonville, CA

  • Average high temperature in December: 53.6°F

The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is December (53.6°F).

  • Average low temperature in December: 37.4°F

The month with the highest average low temperature is July (53.6°F).
The coldest month (with the lowest average low temperature) is December (37.4°F).

Average pressure in December
Boonville, CA

  • Average pressure in December: 30.11"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
Boonville, CA

  • Average wind speed in December: 4.5mph

The windiest months (with the highest average wind speed) are April, May and June (5.5mph).
The calmest month (with the lowest average wind speed) is November (4.2mph).

Average humidity in December
Boonville, CA

  • Average humidity in December: 76%

The month with the highest relative humidity is March (79%).
The months with the lowest relative humidity are July and September (58%).

Average rainfall in December
Boonville, CA

  • Average rainfall in December: 3.11"

The wettest months (with the highest rainfall) are February and December (3.11").
The driest months (with the least rainfall) are July and August (0.08").

Average rainfall days in December
Boonville, CA

  • Average rainfall days in December: 12.5 days

The month with the highest number of rainy days is March (14.3 days).
The month with the least rainy days is August (1.3 days).

Average snowfall in December
Boonville, CA

  • Average snowfall in December: 0"

The month with the highest snowfall is February (0.04").
The months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").

Average snowfall days in December
Boonville, CA

  • Average snowfall days in December: 0 days

The month with the highest number of snowfall days is February (0.3 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
Boonville, CA

  • Average daylight in December: 9h and 30min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in December: 5h and 18min

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 18min).

Average sunshine days in December
Boonville, CA

  • Average sunshine days in December: 17.6 days

The month with the most sunshine days is July (28.5 days).
The month with the least sunshine days is March (15.9 days).

Average UV index in December
Boonville, CA

  • Average UV index in December: 3

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are February and November (UV index 2).

Average cloud cover in December
Boonville, CA

  • Average cloud cover in December: 42

The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is August (Cloud cover 6).

Average visibility in December
Boonville, CA

  • Average visibility in December: 5mi

The months with the highest visibility are February, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, March and December (5mi).