December weather forecast
Castlewood, CO

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Weather in December

The first month of the winter, December, is still a cold month in Castlewood, Colorado, with an average temperature varying between 40.3°F (4.6°C) and 20.7°F (-6.3°C).

Temperature

Castlewood's temperature records reveal December as the coldest month, marked by average highs of 40.3°F (4.6°C) and lows of 20.7°F (-6.3°C).

Humidity

In December, the average relative humidity is 61%.

Rainfall

In Castlewood, in December, it is raining for 4.4 days, with typically 0.51" (13mm) of accumulated precipitation. Throughout the year, there are 94.2 rainfall days, and 11.97" (304mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, October through December. In Castlewood, in December, snow falls for 7.6 days, with typically accumulated 3.39" (86mm) of snow. Throughout the year, there are 46.5 snowfall days, and 37.2" (945mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 9h and 24min of daylight.
On the first day of the month, sunrise is at 7:01 am and sunset at 4:36 pm. On the last day of December, sunrise is at 7:20 am and sunset at 4:45 pm MST.

Sunshine

In Castlewood, the average sunshine in December is 7h.

UV index

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: An average UV index of 2 in December transforms into this advice:
Apart from children, who require continuous protection, most can endure sun exposure for up to an hour without experiencing burns. The solar radiation around mid-day is intense; avoid the Sun and stay safe. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.

Frequently asked questions

What month is the coldest?

December is the coldest month, exhibiting average temperatures of 40.3°F (4.6°C) at the peak and 20.7°F (-6.3°C) at the base.

How cold is it in December?

During December, Castlewood experiences an average high-temperature of 40.3°F (4.6°C) and a low-temperature of 20.7°F (-6.3°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, in August is evaluated at 84.2°F (29°C).

What is the average humidity in December?

In Castlewood, the average relative humidity in December is 61%.

How much does it rain in December?

In Castlewood, during December, the rain falls for 4.4 days and regularly aggregates up to 0.51" (13mm) of precipitation.

How many days does it snow in December?

In Castlewood, during December, snow falls for 7.6 days and regularly aggregates up to 3.39" (86mm) of snow.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 9h and 24min of daylight.

How many hours of daylight does Castlewood have in December?

In Castlewood, the average day length in December is 9h and 26min.

What time are sunrise and sunset in December?

On the first day of December in Castlewood, sunrise is at 7:01 am and sunset at 4:36 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 4:45 pm MST.

How many hours of sunshine does Castlewood have in December?

In December, the average sunshine duration is 7h.

When is the lowest UV index?

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

What is the UV index intensity in December?

In December, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a low health threat from unsafe 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
Castlewood, CO

Average temperature in December - Castlewood, CO
  • Average high temperature in December: 40.3°F

The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is December (40.3°F).

  • Average low temperature in December: 20.7°F

The month with the highest average low temperature is July (59.2°F).
The coldest month (with the lowest average low temperature) is December (20.7°F).

Average pressure in December
Castlewood, CO

Average pressure in December - Castlewood, CO
  • Average pressure in December: 30.11"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are April and June (29.91"Hg).

Average wind speed in December
Castlewood, CO

Average wind speed in December - Castlewood, CO
  • Average wind speed in December: 6.5mph

The windiest month (with the highest average wind speed) is April (7.8mph).
The calmest months (with the lowest average wind speed) are August and December (6.5mph).

Average humidity in December
Castlewood, CO

Average humidity in December - Castlewood, CO
  • Average humidity in December: 61%

The month with the highest relative humidity is February (65%).
The months with the lowest relative humidity are June, August and September (43%).

Average rainfall in December
Castlewood, CO

Average rainfall in December - Castlewood, CO
  • Average rainfall in December: 0.51"

The wettest month (with the highest rainfall) is May (2.2").
The driest month (with the least rainfall) is September (0.47").

Average rainfall days in December
Castlewood, CO

Average rainfall days in December - Castlewood, CO
  • Average rainfall days in December: 4.4 days

The month with the highest number of rainy days is May (14.2 days).
The month with the least rainy days is November (3.4 days).

Average snowfall in December
Castlewood, CO

Average snowfall in December - Castlewood, CO
  • Average snowfall in December: 3.39"

The month with the highest snowfall is April (6.34").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Castlewood, CO

Average snowfall days in December - Castlewood, CO
  • Average snowfall days in December: 7.6 days

The month with the highest number of snowfall days is February (9.4 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in December /
Average sunshine in December
Castlewood, CO

Average daylight in December / Average sunshine in December - Castlewood, CO
  • Average daylight in December: 9h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in December: 7h and 0min

The months with the most sunshine are June and July (Average sunshine: 11h and 54min).
The month with the least sunshine is February (Average sunshine: 6h and 48min).

Average sunshine days in December
Castlewood, CO

Average sunshine days in December - Castlewood, CO
  • Average sunshine days in December: 21.5 days

The month with the most sunshine days is November (23.2 days).
The month with the least sunshine days is April (12.7 days).

Average UV index in December
Castlewood, CO

Average UV index in December - Castlewood, CO
  • Average UV index in December: 2

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in December
Castlewood, CO

Average cloud cover in December - Castlewood, CO
  • Average cloud cover in December: 22

The month with the most cloud cover is April (Cloud cover 26).
The months with the least cloud cover are June and September (Cloud cover 15).

Average visibility in December
Castlewood, CO

Average visibility in December - Castlewood, CO
  • 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).

Castlewood, Colorado, USA

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