December weather forecast
Thornton, CA

englishespañol中文
Share

Weather in December

The first month of the winter, December, is still a cool month in Thornton, California, with an average temperature varying between 55°F (12.8°C) and 41°F (5°C).

Temperature

The lowest temperatures are recorded in December, with averages reaching a high of 55°F (12.8°C) and a low of 41°F (5°C).

Humidity

In Thornton, the average relative humidity in December is 71%.

Rainfall

In Thornton, California, in December, during 8.2 rainfall days, 1.97" (50mm) of precipitation is typically accumulated. Throughout the year, there are 63.8 rainfall days, and 12.6" (320mm) of precipitation is accumulated.

Snowfall

December is the only month when snow falls in Thornton. The month with the most snowfall days is December, when 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

December has the least sunshine of the year in Thornton, with an average of 5.9h of sunshine.

UV index

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 3. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index, 3 in December, converts into the following recommendations:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. To avoid the Sun's strongest rays, limit exposure around the mid-day period. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Attention! Nearly twice the Sun's UV radiation can be reflected by snow.
[Resources]

Frequently asked questions

What are the coldest months in Thornton?

December, recording an average high temperature of 55°F (12.8°C) and a low temperature of 41°F (5°C), is Thornton's coldest month.

What are December temperatures in Thornton?

An average high-temperature, in December, in Thornton, is 55°F (12.8°C) and the average low-temperature is 41°F (5°C). The average heat index (a.k.a. 'real feel', 'felt air temperature'), which calculates the temperature value influenced by the moisture in the air, in September is estimated at 89.6°F (32°C).

What is the average humidity in December in Thornton?

The average relative humidity in December in Thornton is 71%.

How many days does it rain in December in Thornton?

In December, in Thornton, the rain falls for 8.2 days. Throughout December, 1.97" (50mm) of precipitation is accumulated.

When does it snow the most in Thornton?

December has the most snowfall days of the year in Thornton, California. Snow falls for 0.1 days.

When does it start to snow in Thornton?

December is the first month it typically snows. Throughout December, there are 0.1 snowfall days.

What is the month with the shortest days in Thornton?

The month with the shortest days in Thornton is December, with an average of 9h and 36min of daylight.

What is the average length of the day in December in Thornton?

The average day length in December in Thornton, California, is 9h and 34min.

When is the sunrise / sunset in December in Thornton?

In December, on the first day of the month, sunrise is at 7:04 am and sunset at 4:45 pm. On the last day of the month, in Thornton, sunrise is at 7:22 am and sunset at 4:55 pm PST.

What is the month with the least sunshine in Thornton?

The month with the least sunshine is December, with an average of 5.9h of sunshine.

How long on average sun shines in December in Thornton?

In Thornton, the average sunshine duration in December is 5.9h.

What is the month with the lowest UV index in Thornton?

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 3.

How high is the UV index in December in Thornton?

The average daily maximum UV index in December is 3. A UV Index value of 3 to 5 symbolizes a medium hazard to health from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Thornton, CA

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).

[Resources]

Average pressure in December
Thornton, CA

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).

[Resources]

Average wind speed in December
Thornton, CA

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).

[Resources]

Average humidity in December
Thornton, CA

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%).

[Resources]

Average rainfall in December
Thornton, CA

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").

[Resources]

Average rainfall days in December
Thornton, CA

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).

[Resources]

Average snowfall days in December
Thornton, CA

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).

[Resources]

Average daylight in December /
Average sunshine in December
Thornton, CA

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).

[Resources]

Average sunshine days in December
Thornton, CA

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).

[Resources]

Average UV index in December
Thornton, CA

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).

[Resources]

Average cloud cover in December
Thornton, CA

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).

[Resources]

Average visibility in December
Thornton, CA

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).

[Resources]

Thornton, California, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location