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
With its high average temperature of 61.7°F (16.5°C) and a low of 46.2°F (7.9°C), December is regarded as the coldest month.Humidity
In Sun Valley, the average relative humidity in December is 53%.Rainfall
December is the month with the most rainfall. Rain falls for 4.6 days and accumulates 1.18" (30mm) of precipitation.Daylight
With an average of 9h and 54min of daylight, December has the shortest days of the year in Sun Valley.On the first day of December, sunrise is at 6:41 am and sunset at 4:43 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 4:54 pm PST.
Sunshine
The months with the least sunshine are January, February and December, with an average of 6.9h of sunshine.UV index
December is the month with the lowest UV index, with an average maximum UV index of 3. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: A maximum high daily UV index of 3 during December translates into the following directions:
Exercise prevention - Warding off sunburn is urged. The solar radiation around mid-day is intense; avoid the Sun and stay safe. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
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 December temperatures?
What is the average humidity in December?
What is the rainiest month?
How much does it rain in Sun Valley in December?
What is the month with the shortest days in Sun Valley?
What is the average length of the day in December?
What time are sunrise and sunset in December?
What are the months with the least sunshine?
How many hours of sunshine does Sun Valley have in December?
What is the month with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Sun Valley, CA
- Average high temperature in December: 61.7°F
The warmest month (with the highest average high temperature) is August (86.5°F).
The month with the lowest average high temperature is December (61.7°F).
- Average low temperature in December: 46.2°F
The month with the highest average low temperature is August (64.8°F).
The coldest month (with the lowest average low temperature) is December (46.2°F).
Average pressure in December
Sun Valley, CA
- Average pressure in December: 30.08"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in December
Sun Valley, CA
- Average wind speed in December: 5.6mph
The windiest month (with the highest average wind speed) is April (5.9mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity in December
Sun Valley, CA
- Average humidity in December: 53%
The month with the highest relative humidity is June (59%).
The month with the lowest relative humidity is November (48%).
Average rainfall in December
Sun Valley, CA
- Average rainfall in December: 1.18"
The wettest month (with the highest rainfall) is December (1.18").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in December
Sun Valley, CA
- Average rainfall days in December: 4.6 days
The month with the highest number of rainy days is March (5.2 days).
The month with the least rainy days is June (1 days).
Average daylight in December /
Average sunshine in December
Sun Valley, CA
- Average daylight in December: 9h and 5min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in December: 6h and 5min
The months with the most sunshine are June, July and August (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 54min).
Average sunshine days in December
Sun Valley, CA
- Average sunshine days in December: 25.5 days
The month with the most sunshine days is October (27.1 days).
The month with the least sunshine days is February (22.9 days).
Average UV index in December
Sun Valley, CA
- Average UV index in December: 3
The months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in December
Sun Valley, CA
- Average cloud cover in December: 21
The months with the most cloud cover are March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 4).
Average visibility in December
Sun Valley, 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).
Sun Valley, California, USA
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