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 fresh 51.8°F (11°C) in November to a frosty 43.3°F (6.3°C). Twin Knolls experiences an average nighttime temperature of 31.3°F (-0.4°C) in the month of December.Humidity
In December, the average relative humidity is 78%.Rainfall
In December, the rain falls for 10.3 days. Throughout December, 2.44" (62mm) of precipitation is accumulated. In Twin Knolls, during the entire year, the rain falls for 158.9 days and collects up to 31.38" (797mm) of precipitation.Snowfall
Months with snowfall are January through April, October through December. In Twin Knolls, in December, during 3.9 snowfall days, 1.69" (43mm) of snow is typically accumulated. In Twin Knolls, during the entire year, snow falls for 21.2 days and aggregates up to 10.55" (268mm) 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 7:09 am and sunset at 4:44 pm. On the last day of December, sunrise is at 7:27 am and sunset at 4:53 pm EST.
Sunshine
In Twin Knolls, the average sunshine in December is 5h.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 estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for the average person.Note: The maximum daily UV index of 2 during December translates into the following directions:
Infants, children, and people with sensitive skin should always have protection against lengthy periods of sun exposure. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
How much does it rain in December?
How many days does it snow in December?
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?
How many hours of sunshine does Twin Knolls have in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Twin Knolls, MD
- Average high temperature in December: 43.3°F
The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in December: 31.3°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (24.8°F).
Average pressure in December
Twin Knolls, MD
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Twin Knolls, MD
- Average wind speed in December: 8.1mph
The windiest month (with the highest average wind speed) is March (8.9mph).
The calmest months (with the lowest average wind speed) are July and August (5.3mph).
Average humidity in December
Twin Knolls, MD
- Average humidity in December: 78%
The month with the highest relative humidity is May (80%).
The months with the lowest relative humidity are January, March, April, July and November (75%).
Average rainfall in December
Twin Knolls, MD
- Average rainfall in December: 2.44"
The wettest month (with the highest rainfall) is August (3.86").
The driest month (with the least rainfall) is February (1.89").
Average rainfall days in December
Twin Knolls, MD
- Average rainfall days in December: 10.3 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is January (8.3 days).
Average snowfall in December
Twin Knolls, MD
- Average snowfall in December: 1.69"
The month with the highest snowfall is March (3.46").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Twin Knolls, MD
- Average snowfall days in December: 3.9 days
The month with the highest number of snowfall days is January (6.6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Twin Knolls, MD
- 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: 5h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in December
Twin Knolls, MD
- Average sunshine days in December: 17.5 days
The month with the most sunshine days is November (18.9 days).
The month with the least sunshine days is May (11.2 days).
Average UV index in December
Twin Knolls, MD
- Average UV index in December: 2
The months with the highest UV index are May, 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
Twin Knolls, MD
- Average cloud cover in December: 47
The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in December
Twin Knolls, MD
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).
Twin Knolls, Maryland, USA
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