December weather forecastSan Luis, CO
December
Weather in December
The first month of the winter, December, is also an icy month in San Luis, Colorado, with temperature in the range of an average low of 11.8°F (-11.2°C) and an average high of 32.2°F (0.1°C).Temperature
As November transitions into December, San Luis sees a drop in the average high-temperature, transitioning from a frosty 43.3°F (6.3°C) to a wintry 32.2°F (0.1°C). During December, an average low-temperature of 11.8°F (-11.2°C) is observed.Humidity
In December, the average relative humidity is 75%.Rainfall
In San Luis, in December, it is raining for 3.3 days, with typically 0.51" (13mm) of accumulated precipitation. Throughout the year, there are 72.2 rainfall days, and 8.82" (224mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through June, September through December. In San Luis, during December, snow falls for 9.7 days and regularly aggregates up to 4.06" (103mm) of snow. Throughout the year, there are 57.6 snowfall days, and 28.58" (726mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 42min of daylight.On the first day of the month, sunrise is at 6:57 am and sunset at 4:44 pm. On the last day of December, sunrise is at 7:15 am and sunset at 4:54 pm MST.
Sunshine
The average sunshine in December is 6.6h.UV index
The months with the lowest UV index are January through March, October through December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: The UV index of 2 during December leads to these advisories:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Be cautious! The UV radiation from the Sun can be magnified almost twofold by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
San Luis, CO
- Average high temperature in December: 32.2°F
The warmest month (with the highest average high temperature) is July (76.6°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in December: 11.8°F
The month with the highest average low temperature is July (50.2°F).
The coldest month (with the lowest average low temperature) is January (9.3°F).
Average pressure in December
San Luis, CO
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is April (29.89"Hg).
Average wind speed in December
San Luis, CO
- Average wind speed in December: 6.4mph
The windiest months (with the highest average wind speed) are April and May (8.9mph).
The calmest month (with the lowest average wind speed) is July (5.5mph).
Average humidity in December
San Luis, CO
- Average humidity in December: 75%
The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is June (38%).
Average rainfall in December
San Luis, CO
- Average rainfall in December: 0.51"
The wettest month (with the highest rainfall) is July (1.61").
The driest month (with the least rainfall) is November (0.43").
Average rainfall days in December
San Luis, CO
- Average rainfall days in December: 3.3 days
The month with the highest number of rainy days is July (13.9 days).
The month with the least rainy days is November (1.3 days).
Average snowfall in December
San Luis, CO
- Average snowfall in December: 4.06"
The month with the highest snowfall is March (5.55").
The months with the least snowfall are July and August (0").
Average snowfall days in December
San Luis, CO
- Average snowfall days in December: 9.7 days
The month with the highest number of snowfall days is February (10.1 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in December /
Average sunshine in December
San Luis, CO
- Average daylight in December: 9h and 42min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in December: 6h and 36min
The month with the most sunshine is June (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 6h and 30min).
Average sunshine days in December
San Luis, CO
- Average sunshine days in December: 21.3 days
The month with the most sunshine days is October (24.1 days).
The month with the least sunshine days is July (13.3 days).
Average UV index in December
San Luis, CO
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in December
San Luis, CO
- Average cloud cover in December: 28
The month with the most cloud cover is January (Cloud cover 31).
The months with the least cloud cover are June and October (Cloud cover 14).
Average visibility in December
San Luis, CO
- Average visibility in December: 5mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).





