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
The transition to December results in a modest reduction in average high-temperature, moving from a cool 53.6°F (12°C) in November to a chilly 45.5°F (7.5°C). In the month of December, the temperature generally rests at an average low of 34.5°F (1.4°C).Humidity
In Harpers Mill, the average relative humidity in December is 76%.Rainfall
In December, the rain falls for 10.4 days. Throughout December, 2.32" (59mm) of precipitation is accumulated. Throughout the year, there are 157.2 rainfall days, and 30.47" (774mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through March, November and December. In December, it is snowing for 2.1 days. Throughout December, 0.39" (10mm) of snow is accumulated. Throughout the year, there are 11.9 snowfall days, and 5.75" (146mm) of snow is accumulated.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year in Harpers Mill.On the first day of December, sunrise is at 7:07 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 4:54 pm EST.
Sunshine
In Harpers Mill, the average sunshine in December is 5.2h.UV index
The months with the lowest UV index are January, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for the average person.Note: In December, the UV index of 2 transforms into the following advice:
While sun exposure does not greatly affect most, individuals with fair skin, babies, and children always need vigilant safeguarding. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in December?
What is the average humidity in December?
How many days 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?
What time are sunrise and sunset in December?
How many hours of sunshine does Harpers Mill have in December?
When is the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Harpers Mill, MD
- Average high temperature in December: 45.5°F
The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is January (38.8°F).
- Average low temperature in December: 34.5°F
The month with the highest average low temperature is July (70.3°F).
The coldest month (with the lowest average low temperature) is January (27.7°F).
Average pressure in December
Harpers Mill, 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
Harpers Mill, MD
- Average wind speed in December: 8.5mph
The windiest months (with the highest average wind speed) are January, February and March (9.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).
Average humidity in December
Harpers Mill, MD
- Average humidity in December: 76%
The month with the highest relative humidity is May (77%).
The months with the lowest relative humidity are March, April and July (72%).
Average rainfall in December
Harpers Mill, MD
- Average rainfall in December: 2.32"
The wettest month (with the highest rainfall) is August (4.09").
The driest month (with the least rainfall) is January (1.81").
Average rainfall days in December
Harpers Mill, MD
- Average rainfall days in December: 10.4 days
The month with the highest number of rainy days is May (18 days).
The months with the least rainy days are January and November (8.4 days).
Average snowfall in December
Harpers Mill, MD
- Average snowfall in December: 0.39"
The month with the highest snowfall is January (2.09").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Harpers Mill, MD
- Average snowfall days in December: 2.1 days
The month with the highest number of snowfall days is January (3.8 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Harpers Mill, 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 54min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).
Average sunshine days in December
Harpers Mill, MD
- Average sunshine days in December: 18.4 days
The month with the most sunshine days is November (19.9 days).
The months with the least sunshine days are May and July (10.8 days).
Average UV index in December
Harpers Mill, 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, November and December (UV index 2).
Average cloud cover in December
Harpers Mill, MD
- Average cloud cover in December: 44
The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in December
Harpers Mill, MD
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Harpers Mill, Maryland, USA
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