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 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
Temperature readings reach their annual highs in December, averaging 55°F (12.8°C) and a minimum average of 41°F (5°C).Humidity
The average relative humidity in December is 71%.Rainfall
In December, the rain falls for 8.2 days. Throughout December, 1.97" (50mm) of precipitation is accumulated. In Thornton, during the entire year, the rain falls for 63.8 days and collects up to 12.6" (320mm) of precipitation.Snowfall
The only month with snowfall is December. December has the most snowfall days of the year in Thornton. Snow falls for 0.1 days.Daylight
With an average of 9h and 36min of daylight, December has the shortest days of the year in Thornton.On the first day of the month, sunrise is at 7:04 am and sunset at 4:45 pm. On the last day of December, sunrise is at 7:22 am and sunset at 4:55 pm PST.
Sunshine
The month with the least sunshine is December, with an average of 5.9h of sunshine.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 estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.Note: An average UV index of 3 in December transforms into this advice:
Exercise prevention - Warding off sunburn is urged. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What month is the coldest?
What are December temperatures?
What is the average humidity in December?
How much does it rain in December?
What is the snowiest month?
When does it start to snow?
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 in Thornton?
What is the month with the least sunshine?
How many hours of sunshine does Thornton have in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Thornton, CA
- Average high temperature in December: 55°F
The warmest month (with the highest average high temperature) is July (93.9°F).
The month with the lowest average high temperature is December (55°F).
- Average low temperature in December: 41°F
The month with the highest average low temperature is August (58.8°F).
The coldest month (with the lowest average low temperature) is December (41°F).
Average pressure in December
Thornton, CA
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Thornton, CA
- Average wind speed in December: 5.2mph
The windiest months (with the highest average wind speed) are February and June (5.8mph).
The calmest month (with the lowest average wind speed) is November (4.4mph).
Average humidity in December
Thornton, CA
- Average humidity in December: 71%
The month with the highest relative humidity is March (75%).
The month with the lowest relative humidity is July (45%).
Average rainfall in December
Thornton, CA
- Average rainfall in December: 1.97"
The wettest month (with the highest rainfall) is February (2.4").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in December
Thornton, CA
- Average rainfall days in December: 8.2 days
The month with the highest number of rainy days is March (12.4 days).
The month with the least rainy days is June (0.9 days).
Average snowfall days in December
Thornton, CA
- Average snowfall days in December: 0.1 days
The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).
Average daylight in December /
Average sunshine in December
Thornton, CA
- Average daylight in December: 9h and 4min
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 36min).
- Average sunshine in December: 5h and 5min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 54min).
Average sunshine days in December
Thornton, CA
- Average sunshine days in December: 21.8 days
The month with the most sunshine days is August (29.3 days).
The month with the least sunshine days is March (17.8 days).
Average UV index in December
Thornton, CA
- Average UV index in December: 3
The month with the highest UV index is June (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in December
Thornton, CA
- Average cloud cover in December: 34
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 4).
Average visibility in December
Thornton, 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).
Thornton, California, USA
Weather forecast for your location
2. Allow the app to use your location