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
As November shifts into December, a minor alteration in temperatures is observed, with average highs reducing from a cool 51.3°F (10.7°C) to a cold 42.6°F (5.9°C). In December, the temperature drops to an average of 30.4°F (-0.9°C) at night.Humidity
In Runnymeade Summit, the average relative humidity in December is 79%.Rainfall
In Runnymeade Summit, in December, it is raining for 9.8 days, with typically 1.77" (45mm) of accumulated precipitation. Throughout the year, there are 157.5 rainfall days, and 27.52" (699mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In Runnymeade Summit, in December, during 3.9 snowfall days, 1.57" (40mm) of snow is typically accumulated. Throughout the year, in Runnymeade Summit, there are 22.3 snowfall days, and 9.76" (248mm) of snow is accumulated.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:10 am and sunset at 4:44 pm. On the last day of December, in Runnymeade Summit, sunrise is at 7:29 am and sunset at 4:54 pm EST.
Sunshine
In Runnymeade Summit, 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 value of 2, and less, symbolizes a low threat to health from unsafe exposure to UV radiation for the ordinary person.Note: An average UV index of 2 in December transforms into this advice:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. During bright days, sunglasses that offer UVA and UVB defense are recommended. Be vigilant! The reflective nature of snow can increase 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 it 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?
When is the sunrise / sunset in December?
How many hours of sunshine does Runnymeade Summit have in December?
What is the month with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Runnymeade Summit, MD
- Average high temperature in December: 42.6°F
The warmest month (with the highest average high temperature) is July (84°F).
The month with the lowest average high temperature is January (36.7°F).
- Average low temperature in December: 30.4°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (23.5°F).
Average pressure in December
Runnymeade Summit, 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
Runnymeade Summit, MD
- Average wind speed in December: 7.7mph
The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest months (with the lowest average wind speed) are July and August (5mph).
Average humidity in December
Runnymeade Summit, MD
- Average humidity in December: 79%
The month with the highest relative humidity is May (80%).
The month with the lowest relative humidity is April (75%).
Average rainfall in December
Runnymeade Summit, MD
- Average rainfall in December: 1.77"
The wettest month (with the highest rainfall) is August (3.23").
The driest month (with the least rainfall) is February (1.61").
Average rainfall days in December
Runnymeade Summit, MD
- Average rainfall days in December: 9.8 days
The month with the highest number of rainy days is May (18 days).
The month with the least rainy days is January (7.6 days).
Average snowfall in December
Runnymeade Summit, MD
- Average snowfall in December: 1.57"
The month with the highest snowfall is March (3.03").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Runnymeade Summit, MD
- Average snowfall days in December: 3.9 days
The month with the highest number of snowfall days is January (6.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Runnymeade Summit, 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
Runnymeade Summit, MD
- Average sunshine days in December: 18.1 days
The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in December
Runnymeade Summit, 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
Runnymeade Summit, MD
- Average cloud cover in December: 47
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 31).
Average visibility in December
Runnymeade Summit, 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).
Runnymeade Summit, Maryland, USA
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