Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
December is the coldest month, exhibiting average temperatures of 56.3°F (13.5°C) at the peak and 41.4°F (5.2°C) at the base.Humidity
In Guerneville, the average relative humidity in December is 76%.Rainfall
In Guerneville, during December, the rain falls for 8.6 days and regularly aggregates up to 2.32" (59mm) of precipitation. In Guerneville, during the entire year, the rain falls for 60.1 days and collects up to 12.87" (327mm) of precipitation.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:11 am and sunset at 4:51 pm. On the last day of December, sunrise is at 7:29 am and sunset at 5:01 pm PST.
Sunshine
With an average of 5.4h of sunshine, December has the least sunshine of the year in Guerneville.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 medium health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In December, a daily UV index of 3 turns into the following recommendations:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. It's recommended to limit sun exposure when its radiation is at its peak during midday. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the coldest in Guerneville?
What is the usual temperature for Guerneville in December?
What is the average humidity in December in Guerneville?
How much does it rain in Guerneville in December?
What is the month with the shortest days in Guerneville?
What is the average length of the day in December in Guerneville?
When are sunrise and sunset in December in Guerneville?
What is the month with the least sunshine in Guerneville?
How long on average sun shines in December in Guerneville?
When is the lowest UV index in Guerneville?
How high is the UV index in December in Guerneville?
Average temperature in December
Guerneville, CA
- Average high temperature in December: 56.3°F
The warmest month (with the highest average high temperature) is August (81°F).
The month with the lowest average high temperature is December (56.3°F).
- Average low temperature in December: 41.4°F
The months with the highest average low temperature are August and September (53.4°F).
The coldest month (with the lowest average low temperature) is December (41.4°F).
Average pressure in December
Guerneville, 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
Guerneville, CA
- Average wind speed in December: 5.2mph
The windiest month (with the highest average wind speed) is May (7.2mph).
The calmest month (with the lowest average wind speed) is November (5mph).
Average humidity in December
Guerneville, CA
- Average humidity in December: 76%
The month with the highest relative humidity is March (77%).
The month with the lowest relative humidity is September (62%).
Average rainfall in December
Guerneville, CA
- Average rainfall in December: 2.32"
The wettest month (with the highest rainfall) is February (3.27").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in December
Guerneville, CA
- Average rainfall days in December: 8.6 days
The month with the highest number of rainy days is March (10.3 days).
The month with the least rainy days is August (0.9 days).
Average daylight in December /
Average sunshine in December
Guerneville, 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 2min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is December (Average sunshine: 5h and 24min).
Average sunshine days in December
Guerneville, CA
- Average sunshine days in December: 21.3 days
The month with the most sunshine days is July (28.9 days).
The month with the least sunshine days is February (19.9 days).
Average UV index in December
Guerneville, 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
Guerneville, CA
- Average cloud cover in December: 39
The month with the most cloud cover is March (Cloud cover 42).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility in December
Guerneville, 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).
Guerneville, California, USA
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