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 average high-temperature slightly decreases in December, shifting from a chilly 45.9°F (7.7°C) in November to an icy 37°F (2.8°C). During December, the average low-temperature is a freezing cold 27.5°F (-2.5°C).Humidity
The average relative humidity in December is 86%.Rainfall
In Harmonsburg, in December, it is raining for 10.8 days, with typically 1.85" (47mm) of accumulated precipitation. In Harmonsburg, during the entire year, the rain falls for 167.5 days and collects up to 24.29" (617mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In December, it is snowing for 16.5 days. Throughout December, 6.02" (153mm) of snow is accumulated. In Harmonsburg, during the entire year, snow falls for 79.8 days and aggregates up to 25.39" (645mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 12min of daylight.On the first day of December, sunrise is at 7:29 am and sunset at 4:51 pm. On the last day of the month, sunrise is at 7:48 am and sunset at 5:01 pm EST.
Sunshine
The average sunshine in December is 2.7h.UV index
December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: A daily maximum UV index of 1 in December translates into the following instructions:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. During bright days, sunglasses that offer UVA and UVB defense are recommended. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
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 December?
What is the month with the shortest days?
How many hours of daylight does Harmonsburg have in December?
When are sunrise and sunset in December?
How long on average sun shines in December?
What is the month with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Harmonsburg, PA
- Average high temperature in December: 37°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (30.4°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 (18.9°F).
Average pressure in December
Harmonsburg, PA
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Harmonsburg, PA
- Average wind speed in December: 8.8mph
The windiest month (with the highest average wind speed) is January (9.2mph).
The calmest month (with the lowest average wind speed) is July (5.7mph).
Average humidity in December
Harmonsburg, PA
- Average humidity in December: 86%
The month with the highest relative humidity is February (89%).
The months with the lowest relative humidity are April, May, June, July and August (80%).
Average rainfall in December
Harmonsburg, PA
- Average rainfall in December: 1.85"
The wettest month (with the highest rainfall) is June (2.72").
The driest month (with the least rainfall) is November (1.42").
Average rainfall days in December
Harmonsburg, PA
- Average rainfall days in December: 10.8 days
The month with the highest number of rainy days is October (17.5 days).
The month with the least rainy days is January (7.6 days).
Average snowfall in December
Harmonsburg, PA
- Average snowfall in December: 6.02"
The month with the highest snowfall is January (6.42").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Harmonsburg, PA
- Average snowfall days in December: 16.5 days
The month with the highest number of snowfall days is January (20.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Harmonsburg, PA
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 2h and 4min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 2h and 24min).
Average sunshine days in December
Harmonsburg, PA
- Average sunshine days in December: 7 days
The month with the most sunshine days is July (12.5 days).
The month with the least sunshine days is February (6.7 days).
Average UV index in December
Harmonsburg, 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
Harmonsburg, PA
- Average cloud cover in December: 73
The month with the most cloud cover is January (Cloud cover 76).
The months with the least cloud cover are July and August (Cloud cover 32).
Average visibility in December
Harmonsburg, PA
- Average visibility in December: 5mi
The months with the highest visibility are April, August, September, October and November (6mi).
The months with the lowest visibility are January and February (4mi).
Harmonsburg, Pennsylvania, USA
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