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
In Thornton, the lowest average temperatures are observed in December, with a high of 34.7°F (1.5°C) and a low of 24.6°F (-4.1°C).Humidity
In Thornton, the average relative humidity in December is 84%.Rainfall
December is the month with the most rainfall. Rain falls for 9.5 days and accumulates 1.93" (49mm) of precipitation.Snowfall
January through May, September through December are months with snowfall. In Thornton, in December, snow falls for 9.6 days, with typically accumulated 4.65" (118mm) of snow. Throughout the year, there are 39.6 snowfall days, and 22.68" (576mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 8h and 36min of daylight.On the first day of December, sunrise is at 7:15 am and sunset at 4:01 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 4:10 pm PST.
Sunshine
The months with the least sunshine are January and December, with an average of 4.6h of sunshine.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low health risk from exposure to the Sun's UV rays for average individuals.Note: In December, a daily UV index of 2 turns into the following recommendations:
While most people can stay under the sun for an hour without burning, children must always be guarded against sun exposure. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the coldest?
How cold is December in Thornton?
What is the average humidity in December?
What is the rainiest month?
How much does it rain in December?
How much does it snow in Thornton in December?
What is the month with the shortest days in Thornton?
What is the average length of the day in December?
What time are sunrise and sunset in December?
What is the month with the least sunshine?
How many hours of sunshine does Thornton have in December?
When is the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Thornton, WA
- Average high temperature in December: 34.7°F
The warmest month (with the highest average high temperature) is August (83.5°F).
The month with the lowest average high temperature is December (34.7°F).
- Average low temperature in December: 24.6°F
The month with the highest average low temperature is August (60.4°F).
The coldest month (with the lowest average low temperature) is December (24.6°F).
Average pressure in December
Thornton, WA
- Average pressure in December: 30.17"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in December
Thornton, WA
- Average wind speed in December: 7mph
The windiest month (with the highest average wind speed) is March (8mph).
The calmest month (with the lowest average wind speed) is August (5.9mph).
Average humidity in December
Thornton, WA
- Average humidity in December: 84%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is August (37%).
Average rainfall in December
Thornton, WA
- Average rainfall in December: 1.93"
The wettest month (with the highest rainfall) is December (1.93").
The driest month (with the least rainfall) is July (0.28").
Average rainfall days in December
Thornton, WA
- Average rainfall days in December: 9.5 days
The month with the highest number of rainy days is April (14.6 days).
The month with the least rainy days is July (4.5 days).
Average snowfall in December
Thornton, WA
- Average snowfall in December: 4.65"
The month with the highest snowfall is February (6.69").
The months with the least snowfall are June, July and August (0").
Average snowfall days in December
Thornton, WA
- Average snowfall days in December: 9.6 days
The months with the highest number of snowfall days are February and December (9.6 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in December /
Average sunshine in December
Thornton, WA
- Average daylight in December: 8h and 4min
The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in December: 4h and 4min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 4h and 36min).
Average sunshine days in December
Thornton, WA
- Average sunshine days in December: 15.5 days
The month with the most sunshine days is July (24.6 days).
The month with the least sunshine days is February (12.2 days).
Average UV index in December
Thornton, WA
- Average UV index in December: 2
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Thornton, WA
- Average cloud cover in December: 53
The months with the most cloud cover are January and December (Cloud cover 53).
The month with the least cloud cover is July (Cloud cover 11).
Average visibility in December
Thornton, WA
- Average visibility in December: 5mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (5mi).
Thornton, Washington, USA
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