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
Mercersville's average high-temperature decreases in December, falling from a cool 51.6°F (10.9°C) in November to an icy 42.3°F (5.7°C). The nights of December in Mercersville anticipate an average low-temperature of 30.2°F (-1°C).Humidity
May, October and December, with an average relative humidity of 79%, are the most humid months.Rainfall
In December, the rain falls for 10.8 days. Throughout December, 2.2" (56mm) of precipitation is accumulated. In Mercersville, during the entire year, the rain falls for 162.4 days and collects up to 30.16" (766mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In Mercersville, in December, snow falls for 4.5 days, with typically accumulated 2.09" (53mm) of snow. In Mercersville, during the entire year, snow falls for 24.4 days and aggregates up to 14.29" (363mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of December, sunrise is at 7:12 am and sunset at 4:47 pm. On the last day of the month, sunrise is at 7:31 am and sunset at 4:57 pm EST.
Sunshine
The average sunshine in December is 4.8h.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 estimate of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for the average person.Note: The UV index of 2 in December translates into these instructions:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the most humid month?
What is the average humidity in December?
How much does it rain in December?
How much 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 Mercersville have in December?
What is the month with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Mercersville, MD
- Average high temperature in December: 42.3°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 (37°F).
- Average low temperature in December: 30.2°F
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in December
Mercersville, 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
Mercersville, MD
- Average wind speed in December: 7mph
The windiest months (with the highest average wind speed) are January, February and March (7.6mph).
The calmest months (with the lowest average wind speed) are July and August (4.5mph).
Average humidity in December
Mercersville, MD
- Average humidity in December: 79%
The months with the highest relative humidity are May, October and December (79%).
The month with the lowest relative humidity is July (74%).
Average rainfall in December
Mercersville, MD
- Average rainfall in December: 2.2"
The wettest month (with the highest rainfall) is July (3.27").
The driest month (with the least rainfall) is January (1.97").
Average rainfall days in December
Mercersville, MD
- Average rainfall days in December: 10.8 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is November (9.4 days).
Average snowfall in December
Mercersville, MD
- Average snowfall in December: 2.09"
The month with the highest snowfall is January (4.72").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Mercersville, MD
- Average snowfall days in December: 4.5 days
The month with the highest number of snowfall days is January (7.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Mercersville, 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: 4h and 5min
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
Mercersville, MD
- Average sunshine days in December: 16.4 days
The month with the most sunshine days is November (18.9 days).
The month with the least sunshine days is April (11 days).
Average UV index in December
Mercersville, 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
Mercersville, MD
- Average cloud cover in December: 49
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in December
Mercersville, MD
- Average visibility in December: 5mi
The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).
Mercersville, Maryland, USA
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