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's onset brings a negligible change in high-temperatures, falling from a fresh 52.2°F (11.2°C) in November to a chilly 43.2°F (6.2°C). Johnsville's average low-temperature for the month of December records at a freezing cold 31.3°F (-0.4°C).Humidity
In Johnsville, the average relative humidity in December is 78%.Rainfall
In December, the rain falls for 9.1 days. Throughout December, 1.02" (26mm) of precipitation is accumulated. Throughout the year, there are 130.3 rainfall days, and 15.47" (393mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, November and December. In Johnsville, during December, snow falls for 2.5 days and regularly aggregates up to 0.47" (12mm) of snow. In Johnsville, during the entire year, snow falls for 16 days and aggregates up to 4.13" (105mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:10 am and sunset at 4:45 pm. On the last day of December, sunrise is at 7:29 am and sunset at 4:55 pm EST.
Sunshine
In December, the average sunshine in Johnsville is 5h.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 hazard from unsafe exposure to UV radiation for the average person.Note: The maximum daily UV index of 2 in December interprets into the following recommendations:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. To protect against the Sun's most potent rays, avoid direct exposure around midday. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in Johnsville in December?
What is the average humidity in December?
How much does it rain in December?
How much does it snow in Johnsville in December?
What is the month with the shortest days?
How many hours of daylight does Johnsville have in December?
When are sunrise and sunset in December?
How many hours of sunshine does Johnsville have in December?
What are the months with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Johnsville, MD
- Average high temperature in December: 43.2°F
The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (37.6°F).
- Average low temperature in December: 31.3°F
The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (25°F).
Average pressure in December
Johnsville, 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
Johnsville, MD
- Average wind speed in December: 8mph
The windiest month (with the highest average wind speed) is March (8.7mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in December
Johnsville, 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, April, July and November (75%).
Average rainfall in December
Johnsville, MD
- Average rainfall in December: 1.02"
The wettest month (with the highest rainfall) is August (2.48").
The driest month (with the least rainfall) is February (0.79").
Average rainfall days in December
Johnsville, MD
- Average rainfall days in December: 9.1 days
The month with the highest number of rainy days is August (15.1 days).
The months with the least rainy days are January and February (6.8 days).
Average snowfall in December
Johnsville, MD
- Average snowfall in December: 0.47"
The month with the highest snowfall is January (1.34").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Johnsville, MD
- Average snowfall days in December: 2.5 days
The month with the highest number of snowfall days is February (4.9 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
Johnsville, 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 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in December
Johnsville, MD
- Average sunshine days in December: 19.3 days
The month with the most sunshine days is November (20.9 days).
The month with the least sunshine days is May (12.9 days).
Average UV index in December
Johnsville, 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
Johnsville, MD
- Average cloud cover in December: 46
The months with the most cloud cover are February and March (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in December
Johnsville, 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).
Johnsville, Maryland, USA
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