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 move into December indicates a slight reduction in the average high-temperature, down from November's fresh 53.1°F (11.7°C) to a chilly 44.1°F (6.7°C). River Mills reports an average nighttime low-temperature of 32.9°F (0.5°C) in December.Humidity
The average relative humidity in December is 76%.Rainfall
In River Mills, in December, it is raining for 11.8 days, with typically 2.6" (66mm) of accumulated precipitation. Throughout the year, there are 165.5 rainfall days, and 31.65" (804mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, November and December. In River Mills, in December, during 2.9 snowfall days, 1.22" (31mm) of snow is typically accumulated. In River Mills, Maryland, during the entire year, snow falls for 16.6 days and aggregates up to 7.8" (198mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 30min of daylight.On the first day of December, sunrise is at 7:08 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 4:54 pm EST.
Sunshine
In River Mills, Maryland, the average sunshine in December is 5.2h.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 of 2, and less, symbolizes a low threat to health from unsafe exposure to UV radiation for the average person.Note: In December, a daily maximum UV index of 2 leads to the following instructions:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Always opt for UVA and UVB-resistant sunglasses on radiant days. 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 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?
What time are sunrise and sunset in December?
How many hours of sunshine does River Mills have in December?
What are the months with the lowest UV index?
What is the UV index intensity in December in River Mills?
Average temperature in December
River Mills, MD
- Average high temperature in December: 44.1°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (38.1°F).
- Average low temperature in December: 32.9°F
The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure in December
River Mills, 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
River Mills, MD
- Average wind speed in December: 8mph
The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in December
River Mills, MD
- Average humidity in December: 76%
The months with the highest relative humidity are May and October (77%).
The month with the lowest relative humidity is July (71%).
Average rainfall in December
River Mills, MD
- Average rainfall in December: 2.6"
The wettest month (with the highest rainfall) is August (3.74").
The driest month (with the least rainfall) is January (2.05").
Average rainfall days in December
River Mills, MD
- Average rainfall days in December: 11.8 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is January (9.7 days).
Average snowfall in December
River Mills, MD
- Average snowfall in December: 1.22"
The month with the highest snowfall is January (2.4").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
River Mills, MD
- Average snowfall days in December: 2.9 days
The month with the highest number of snowfall days is January (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
River Mills, 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
River Mills, MD
- Average sunshine days in December: 16.2 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is May (10.4 days).
Average UV index in December
River Mills, 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
River Mills, MD
- Average cloud cover in December: 44
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in December
River Mills, 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).
River Mills, Maryland, USA
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