December weather forecastCastle Rock, MN
December
Weather in December
The first month of the winter, December, is also a subzero cold month in Castle Rock, Minnesota, with an average temperature fluctuating between 26.1°F (-3.3°C) and 15.4°F (-9.2°C).Temperature
The start of December signals a clear decrease in the average high-temperature, falling from a cold 41°F (5°C) in November to a subzero cold 26.1°F (-3.3°C). In Castle Rock, the average nighttime temperature during December is a still freezing cold 15.4°F (-9.2°C).Humidity
In December, the average relative humidity is 89%.Rainfall
In December, the rain falls for 4.3 days. Throughout December, 1.26" (32mm) of precipitation is accumulated. Throughout the year, there are 126.4 rainfall days, and 24.76" (629mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In December, it is snowing for 11.6 days. Throughout December, 4.21" (107mm) of snow is accumulated. In Castle Rock, during the entire year, snow falls for 55.6 days and aggregates up to 22.36" (568mm) of snow.Daylight
The month with the shortest days in Castle Rock, Minnesota, is December, with an average of 8h and 54min of daylight.On the first day of the month, sunrise is at 7:29 am and sunset at 4:34 pm. On the last day of December, sunrise is at 7:49 am and sunset at 4:42 pm CST.
Sunshine
The average sunshine in December is 3.5h.UV index
January, February, November and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In December, an average UV index of 1 transforms into the following instructions:
Most individuals face no significant issues with extended sun exposure, but it is always essential to protect children, babies, and those with sensitive skin. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Castle Rock, MN
- Average high temperature in December: 26.1°F
The warmest month (with the highest average high temperature) is July (79.5°F).
The month with the lowest average high temperature is January (20.8°F).
- Average low temperature in December: 15.4°F
The month with the highest average low temperature is July (62.4°F).
The coldest month (with the lowest average low temperature) is January (7.7°F).
Average pressure in December
Castle Rock, MN
- Average pressure in December: 30.11"Hg
The months with the highest atmospheric pressure are January and February (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in December
Castle Rock, MN
- Average wind speed in December: 8.3mph
The windiest month (with the highest average wind speed) is April (9.5mph).
The calmest month (with the lowest average wind speed) is July (7mph).
Average humidity in December
Castle Rock, MN
- Average humidity in December: 89%
The month with the highest relative humidity is January (91%).
The months with the lowest relative humidity are April and October (73%).
Average rainfall in December
Castle Rock, MN
- Average rainfall in December: 1.26"
The wettest month (with the highest rainfall) is June (4.21").
The driest month (with the least rainfall) is January (0.75").
Average rainfall days in December
Castle Rock, MN
- Average rainfall days in December: 4.3 days
The month with the highest number of rainy days is June (17.4 days).
The month with the least rainy days is February (2.8 days).
Average snowfall in December
Castle Rock, MN
- Average snowfall in December: 4.21"
The month with the highest snowfall is February (6.1").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Castle Rock, MN
- Average snowfall days in December: 11.6 days
The month with the highest number of snowfall days is January (13.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Castle Rock, MN
- Average daylight in December: 8h and 54min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in December: 3h and 30min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).
Average sunshine days in December
Castle Rock, MN
- Average sunshine days in December: 16.9 days
The month with the most sunshine days is November (17.3 days).
The month with the least sunshine days is June (10.2 days).
Average UV index in December
Castle Rock, MN
- Average UV index in December: 1
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in December
Castle Rock, MN
- Average cloud cover in December: 64
The month with the most cloud cover is January (Cloud cover 68).
The months with the least cloud cover are July and August (Cloud cover 32).
Average visibility in December
Castle Rock, MN
- Average visibility in December: 5mi
The months with the highest visibility are April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and February (4mi).
