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 month when Halcyon experiences its coldest temperatures, averaging a high of 61.2°F (16.2°C) and a low of 46.8°F (8.2°C).Humidity
In Halcyon, California, the average relative humidity in December is 63%.Rainfall
In December, in Halcyon, the rain falls for 6.4 days. Throughout December, 1.02" (26mm) of precipitation is accumulated. In Halcyon, during the entire year, the rain falls for 47.6 days and collects up to 6.93" (176mm) of precipitation.Daylight
December has the shortest days of the year, with an average of 9h and 48min of daylight.On the first day of December, sunrise is at 6:52 am and sunset at 4:50 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 5:01 pm PST.
Sunshine
The months with the least sunshine are February and December, with an average of 6.5h of sunshine.UV index
The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for average individuals.Note: A maximum daily UV index of 4 during December morphs into the following directions:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the coldest time of year?
What are December temperatures?
What is the average humidity in December?
How much does it rain in December?
What is the month with the shortest days?
What is the average length of the day in December?
When are sunrise and sunset in December?
What are the months with the least sunshine in Halcyon?
How many hours of sunshine does Halcyon have in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Halcyon, CA
- Average high temperature in December: 61.2°F
The warmest month (with the highest average high temperature) is September (79.5°F).
The month with the lowest average high temperature is December (61.2°F).
- Average low temperature in December: 46.8°F
The month with the highest average low temperature is September (59.9°F).
The coldest month (with the lowest average low temperature) is February (46°F).
Average pressure in December
Halcyon, CA
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.91"Hg).
Average wind speed in December
Halcyon, CA
- Average wind speed in December: 6.5mph
The windiest months (with the highest average wind speed) are April and May (7.3mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).
Average humidity in December
Halcyon, CA
- Average humidity in December: 63%
The month with the highest relative humidity is March (68%).
The month with the lowest relative humidity is October (58%).
Average rainfall in December
Halcyon, CA
- Average rainfall in December: 1.02"
The wettest month (with the highest rainfall) is March (1.61").
The driest months (with the least rainfall) are June and August (0.04").
Average rainfall days in December
Halcyon, CA
- Average rainfall days in December: 6.4 days
The month with the highest number of rainy days is March (8.4 days).
The month with the least rainy days is August (0.8 days).
Average daylight in December /
Average sunshine in December
Halcyon, CA
- Average daylight in December: 9h and 5min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in December: 6h and 3min
The months with the most sunshine are June, July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are February and December (Average sunshine: 6h and 30min).
Average sunshine days in December
Halcyon, CA
- Average sunshine days in December: 24 days
The month with the most sunshine days is August (29.6 days).
The month with the least sunshine days is February (21 days).
Average UV index in December
Halcyon, CA
- Average UV index in December: 4
The months with the highest UV index are June and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 4).
Average cloud cover in December
Halcyon, CA
- Average cloud cover in December: 25
The month with the most cloud cover is March (Cloud cover 27).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in December
Halcyon, 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).
Halcyon, California, USA
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