December weather forecastCastle Rock, CO
December
Weather in December
December in Castle Rock is the onset of the winter season with temperatures dropping to an average low of 20.1°F (-6.6°C). Compared to November, it’s a much colder month, characterized by the typical winter chills. Snowfall measures about 3.86" (98mm), turning the city into a winter wonderland. The shorter daylight hours and frosty weather signal the full grip of winter. Despite the cold, the holiday spirit combined with the beautiful white scenery makes December an enchanting time in Castle Rock.Temperature
December, marked by an average high-temperature of 39.6°F (4.2°C) and a low-temperature of 20.1°F (-6.6°C), is the coldest month in Castle Rock.Humidity
The average relative humidity in December is 62%.Rainfall
The months with the least rainfall in Castle Rock are January and December Rain falls for 5.5 days and accumulates 0.55" (14mm) of rain.Snowfall
January through June, October through December are months with snowfall in Castle Rock. In December, in Castle Rock, it is snowing for 8.4 days. Throughout December, 3.86" (98mm) of snow is accumulated. In Castle Rock, during the entire year, snow falls for 51 days and aggregates up to 40.43" (1027mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:00 am and sunset at 4:36 pm. On the last day of December, sunrise is at 7:19 am and sunset at 4:46 pm MST.
Sunshine
In December, the average sunshine is 7h.UV index
January, February, October through December, with an average maximum UV index of 2, are months with the lowest UV index in Castle Rock. A UV Index estimate of 2, and below, represents a low threat to health from unsafe exposure to UV radiation for ordinary individuals.Note: The daily high UV index of 2 during December translates into the following recommendations:
Prolonged sun exposure generally does not trouble most people. However, it is vital to ensure protection for babies, children, and individuals with sensitive skin. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays. Take into account! The reflection from snow can nearly double the Sun's UV radiation intensity.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Castle Rock, CO
- Average high temperature in December: 39.6°F
The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is December (39.6°F).
- Average low temperature in December: 20.1°F
The month with the highest average low temperature is July (57.2°F).
The coldest month (with the lowest average low temperature) is December (20.1°F).
Average pressure in December
Castle Rock, 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
Castle Rock, CO
- Average wind speed in December: 6.8mph
The windiest month (with the highest average wind speed) is April (7.9mph).
The calmest months (with the lowest average wind speed) are July, August and September (6.5mph).
Average humidity in December
Castle Rock, CO
- Average humidity in December: 62%
The month with the highest relative humidity is February (66%).
The months with the lowest relative humidity are June and September (45%).
Average rainfall in December
Castle Rock, CO
- Average rainfall in December: 0.55"
The wettest month (with the highest rainfall) is May (2.24").
The driest months (with the least rainfall) are January and December (0.55").
Average rainfall days in December
Castle Rock, CO
- Average rainfall days in December: 5.5 days
The month with the highest number of rainy days is July (15.1 days).
The month with the least rainy days is November (3 days).
Average snowfall in December
Castle Rock, CO
- Average snowfall in December: 3.86"
The month with the highest snowfall is April (7.13").
The months with the least snowfall are July, August and September (0").
Average snowfall days in December
Castle Rock, CO
- Average snowfall days in December: 8.4 days
The month with the highest number of snowfall days is February (9.8 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in December /
Average sunshine in December
Castle Rock, CO
- Average daylight in December: 9h and 24min
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, July and August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 6h and 48min).
Average sunshine days in December
Castle Rock, CO
- Average sunshine days in December: 20.5 days
The month with the most sunshine days is November (22.8 days).
The month with the least sunshine days is July (10.6 days).
Average UV index in December
Castle Rock, CO
- Average UV index in December: 2
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in December
Castle Rock, CO
- Average cloud cover in December: 22
The month with the most cloud cover is April (Cloud cover 27).
The month with the least cloud cover is September (Cloud cover 15).
Average visibility in December
Castle Rock, 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).
