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
In December, the meteorological conditions change slightly, with the average high-temperature moving from a fresh 53.4°F (11.9°C) in November to a frosty 45.5°F (7.5°C). December nights in Potomac observe an average temperature dip to a cold 32.9°F (0.5°C).Humidity
The months with the highest humidity in Potomac are October and December, with an average relative humidity of 76%.Rainfall
In December, in Potomac, the rain falls for 9.8 days. Throughout December, 2.36" (60mm) of precipitation is accumulated. In Potomac, during the entire year, the rain falls for 156.5 days and collects up to 30.71" (780mm) of precipitation.Snowfall
January through April, November and December are months with snowfall in Potomac. In Potomac, in December, during 2.5 snowfall days, 1.57" (40mm) of snow is typically accumulated. Throughout the year, there are 15.5 snowfall days, and 10.24" (260mm) of snow is accumulated.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year in Potomac.On the first day of December in Potomac, Maryland, sunrise is at 7:09 am and sunset at 4:46 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 4:56 pm EST.
Sunshine
In December, the average sunshine in Potomac is 5.1h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for the average person.Note: In December, the UV index of 2 transforms into the following advice:
Apart from children, who require continuous protection, most can endure sun exposure for up to an hour without experiencing burns. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. During bright days, sunglasses that offer UVA and UVB defense are recommended. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
Frequently asked questions
What are the temperatures in Potomac in December?
What is the most humid month in Potomac?
What is the average humidity in December in Potomac?
How much does it rain in Potomac in December?
How many days does it snow in December in Potomac?
What is the month with the shortest days in Potomac?
How many hours of daylight does Potomac have in December?
When are sunrise and sunset in December in Potomac?
How long on average sun shines in December in Potomac?
What are the months with the lowest UV index in Potomac?
What is the UV index reading in December in Potomac?
Average temperature in December
Potomac, MD
- Average high temperature in December: 45.5°F
The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (39.4°F).
- Average low temperature in December: 32.9°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.4°F).
Average pressure in December
Potomac, 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 (29.95"Hg).
Average wind speed in December
Potomac, MD
- Average wind speed in December: 6.9mph
The windiest month (with the highest average wind speed) is March (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.9mph).
Average humidity in December
Potomac, MD
- Average humidity in December: 76%
The months with the highest relative humidity are October and December (76%).
The month with the lowest relative humidity is July (69%).
Average rainfall in December
Potomac, MD
- Average rainfall in December: 2.36"
The wettest month (with the highest rainfall) is August (3.86").
The driest month (with the least rainfall) is February (1.93").
Average rainfall days in December
Potomac, MD
- Average rainfall days in December: 9.8 days
The month with the highest number of rainy days is August (17.3 days).
The month with the least rainy days is January (8.1 days).
Average snowfall in December
Potomac, MD
- Average snowfall in December: 1.57"
The month with the highest snowfall is March (3.03").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Potomac, MD
- Average snowfall days in December: 2.5 days
The month with the highest number of snowfall days is February (4.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Potomac, MD
- Average daylight in December: 9h and 3min
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 30min).
- Average sunshine in December: 5h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 0min).
Average sunshine days in December
Potomac, MD
- Average sunshine days in December: 18.4 days
The month with the most sunshine days is November (19.9 days).
The month with the least sunshine days is May (11.7 days).
Average UV index in December
Potomac, 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
Potomac, MD
- Average cloud cover in December: 46
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in December
Potomac, MD
- 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).
Potomac, Maryland, USA
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