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 snowfall in December
- Average snowfall 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, known for its average high temperature of 52.9°F (11.6°C) and an average low temperature of 40.1°F (4.5°C), is the coldest month.Humidity
In December, the average relative humidity is 81%.Rainfall
The month with the most rainfall is December, when the rain falls for 14.8 days and typically aggregates up to 4.96" (126mm) of precipitation.Snowfall
In Rio Dell, snow does not fall in January, March through December.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:21 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 7:39 am and sunset at 4:59 pm PST.
Sunshine
With an average of 5h of sunshine, December has the least sunshine of the year.UV index
January through March, November and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for the average person.Note: In December, a daily maximum UV index of 3 leads to the following instructions:
Be vigilant - Suggestions to stave off sun damage are provided. To protect against the Sun's most potent rays, avoid direct exposure around midday. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What time of the year is the coldest?
What are the temperatures in Rio Dell in December?
What is the average humidity in December?
What is the wettest month?
How many days does it rain in December?
When it does not snow?
What is the month with the shortest days?
What is the average length of the day in December in Rio Dell?
When are sunrise and sunset in December?
What is the month with the least sunshine?
How long on average sun shines in December?
What are the months with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Rio Dell, CA
- Average high temperature in December: 52.9°F
The warmest month (with the highest average high temperature) is August (74.1°F).
The month with the lowest average high temperature is December (52.9°F).
- Average low temperature in December: 40.1°F
The month with the highest average low temperature is August (51.8°F).
The coldest month (with the lowest average low temperature) is February (39.7°F).
Average pressure in December
Rio Dell, 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 August and September (29.96"Hg).
Average wind speed in December
Rio Dell, CA
- Average wind speed in December: 7mph
The windiest month (with the highest average wind speed) is June (7.7mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).
Average humidity in December
Rio Dell, CA
- Average humidity in December: 81%
The month with the highest relative humidity is March (83%).
The month with the lowest relative humidity is September (73%).
Average rainfall in December
Rio Dell, CA
- Average rainfall in December: 4.96"
The wettest month (with the highest rainfall) is December (4.96").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days in December
Rio Dell, CA
- Average rainfall days in December: 14.8 days
The month with the highest number of rainy days is March (17.3 days).
The months with the least rainy days are July and August (1.8 days).
Average snowfall in December
Rio Dell, CA
- Average snowfall in December: 0"
The month with the highest snowfall is February (0.59").
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
Rio Dell, CA
- Average snowfall days in December: 0.1 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 and November (0 days).
Average daylight in December /
Average sunshine in December
Rio Dell, CA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 5h and 0min
The months with the most sunshine are July and August (Average sunshine: 11h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).
Average sunshine days in December
Rio Dell, CA
- Average sunshine days in December: 15.1 days
The month with the most sunshine days is July (28.5 days).
The month with the least sunshine days is March (11.9 days).
Average UV index in December
Rio Dell, CA
- Average UV index in December: 3
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 3).
Average cloud cover in December
Rio Dell, CA
- Average cloud cover in December: 45
The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in December
Rio Dell, CA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, September, October, November and December (6mi).
The months with the lowest visibility are May, July and August (5mi).
Rio Dell, California, USA
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