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 onset of December is marked by a decrease in temperature, transitioning from a frosty 48.4°F (9.1°C) in November to an icy 38.3°F (3.5°C). During December, the nighttime temperature averages to a subzero cold 27.5°F (-2.5°C).Humidity
In December, the average relative humidity is 85%.Rainfall
In Harmony, during December, the rain falls for 11.9 days and regularly aggregates up to 2.87" (73mm) of precipitation. Throughout the year, in Harmony, there are 184.5 rainfall days, and 36.54" (928mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In December, it is snowing for 13 days. Throughout December, 4.49" (114mm) of snow is accumulated. In Harmony, Pennsylvania, during the entire year, snow falls for 63.9 days and aggregates up to 24.06" (611mm) of snow.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:26 am and sunset at 4:53 pm. On the last day of the month, sunrise is at 7:44 am and sunset at 5:03 pm EST.
Sunshine
In December, the average sunshine is 3.2h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: An average maximum UV index of 1 in December leads to these recommendations:
While most can endure approximately an hour in the sun without burning, children always require protection from sunlight. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
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 much does it rain in December?
How much does it snow in Harmony in December?
What is the month with the shortest days in Harmony?
How many hours of daylight does Harmony have in December?
When is the sunrise / sunset in December?
How long on average sun shines in December?
What is the month with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Harmony, PA
- Average high temperature in December: 38.3°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (31.8°F).
- Average low temperature in December: 27.5°F
The month with the highest average low temperature is July (61°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).
Average pressure in December
Harmony, PA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Harmony, PA
- Average wind speed in December: 7.4mph
The windiest month (with the highest average wind speed) is January (8.1mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).
Average humidity in December
Harmony, PA
- Average humidity in December: 85%
The months with the highest relative humidity are January and February (86%).
The months with the lowest relative humidity are April, July and August (77%).
Average rainfall in December
Harmony, PA
- Average rainfall in December: 2.87"
The wettest month (with the highest rainfall) is April (3.82").
The driest month (with the least rainfall) is November (2.24").
Average rainfall days in December
Harmony, PA
- Average rainfall days in December: 11.9 days
The month with the highest number of rainy days is May (20.6 days).
The month with the least rainy days is January (10.3 days).
Average snowfall in December
Harmony, PA
- Average snowfall in December: 4.49"
The month with the highest snowfall is January (6.38").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Harmony, PA
- Average snowfall days in December: 13 days
The month with the highest number of snowfall days is January (17.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Harmony, PA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 3h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 2h and 48min).
Average sunshine days in December
Harmony, PA
- Average sunshine days in December: 9.8 days
The month with the most sunshine days is November (14.3 days).
The month with the least sunshine days is February (7.2 days).
Average UV index in December
Harmony, PA
- Average UV index in December: 1
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Harmony, PA
- Average cloud cover in December: 67
The month with the most cloud cover is January (Cloud cover 71).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in December
Harmony, PA
- Average visibility in December: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January and February (4mi).
Harmony, Pennsylvania, USA
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