Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
December brings a slight decrease in temperature, down from a refreshing 60.6°F (15.9°C) in November to a cool 53.8°F (12.1°C). During the month of December, an average temperature of 38.5°F (3.6°C) is noted during the nights.Humidity
December is the most humid month, with an average relative humidity of 77%.Rainfall
In San Mateo, South Carolina, during December, the rain falls for 10.5 days and regularly aggregates up to 1.69" (43mm) of precipitation. Throughout the year, there are 136.3 rainfall days, and 19.02" (483mm) of precipitation is accumulated.Snowfall
January through March and December are months with snowfall. December is the first month it typically snows in San Mateo, South Carolina. Throughout December, in the average 0.4 snowfall days, it receives 0.2" (5mm) of snow. In San Mateo, during the entire year, snow falls for 2.3 days and aggregates up to 0.79" (20mm) of snow.Daylight
With an average of 9h and 54min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:19 am and sunset at 5:20 pm. On the last day of the month, sunrise is at 7:37 am and sunset at 5:30 pm EST.
Sunshine
With an average of 5.1h of sunshine, December has the least sunshine of the year.UV index
January and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for average individuals.Note: The maximum daily UV index, 2 in December, converts into the following recommendations:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. Sun's radiation is most powerful around mid-day, so it's best to limit outdoor activities during this time. Experience reduced UV exposure by about half when donning a wide-brim hat. Be aware! The intensity of the Sun's UV radiation can be amplified nearly twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in December?
What is the most humid month?
What is the average humidity in December?
How much does it rain in December?
When does it start snowing in San Mateo?
What is the month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December?
What is the month with the least sunshine in San Mateo?
How long on average sun shines in December?
What are the months with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
San Mateo, SC
- Average high temperature in December: 53.8°F
The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is January (50.2°F).
- Average low temperature in December: 38.5°F
The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (34.5°F).
Average pressure in December
San Mateo, SC
- Average pressure in December: 30.14"Hg
The months with the highest atmospheric pressure are January and November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.99"Hg).
Average wind speed in December
San Mateo, SC
- Average wind speed in December: 6.4mph
The windiest month (with the highest average wind speed) is February (7mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in December
San Mateo, SC
- Average humidity in December: 77%
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is July (69%).
Average rainfall in December
San Mateo, SC
- Average rainfall in December: 1.69"
The wettest month (with the highest rainfall) is August (2.28").
The driest month (with the least rainfall) is September (0.79").
Average rainfall days in December
San Mateo, SC
- Average rainfall days in December: 10.5 days
The month with the highest number of rainy days is July (15.4 days).
The month with the least rainy days is October (7.2 days).
Average snowfall in December
San Mateo, SC
- Average snowfall in December: 0.2"
The month with the highest snowfall is February (0.31").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in December
San Mateo, SC
- Average snowfall days in December: 0.4 days
The month with the highest number of snowfall days is January (0.9 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).
Average daylight in December /
Average sunshine in December
San Mateo, SC
- Average daylight in December: 9h and 5min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in December: 5h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).
Average sunshine days in December
San Mateo, SC
- Average sunshine days in December: 18.4 days
The month with the most sunshine days is October (22.6 days).
The month with the least sunshine days is July (14.3 days).
Average UV index in December
San Mateo, SC
- Average UV index in December: 2
The month with the highest UV index is June (UV index 7).
The months with the lowest UV index are January and December (UV index 2).
Average cloud cover in December
San Mateo, SC
- Average cloud cover in December: 44
The month with the most cloud cover is February (Cloud cover 45).
The months with the least cloud cover are June and July (Cloud cover 29).
Average visibility in December
San Mateo, SC
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
San Mateo, South Carolina, USA
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