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
With December's arrival, Harleysville sees a decrease in average high-temperatures, moving from a fresh 50.9°F (10.5°C) in November to a cold 41.5°F (5.3°C). Throughout December, Harleysville registers a consistent average low-temperature of 30.4°F (-0.9°C).Humidity
The average relative humidity in December is 80%.Rainfall
In Harleysville, during December, the rain falls for 8 days and regularly aggregates up to 1.34" (34mm) of precipitation. Throughout the year, there are 128.6 rainfall days, and 15.16" (385mm) of precipitation is accumulated.Snowfall
January through May, November and December are months with snowfall. In December, it is snowing for 2 days. Throughout December, 1.34" (34mm) of snow is accumulated. Throughout the year, in Harleysville, there are 17 snowfall days, and 5.43" (138mm) of snow is accumulated.Daylight
The month with the shortest days in Harleysville is December, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:05 am and sunset at 4:36 pm. On the last day of December, in Harleysville, sunrise is at 7:24 am and sunset at 4:45 pm EST.
Sunshine
In Harleysville, the average sunshine in December is 4.8h.UV index
The months with the lowest UV index in Harleysville are January through March, November and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 2 during December leads to these advisories:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Frequently asked questions
How cold is it in Harleysville in December?
What is the average humidity in December in Harleysville?
How much does it rain in Harleysville in December?
How much does it snow in Harleysville in December?
What is the month with the shortest days in Harleysville?
What is the average length of the day in December in Harleysville?
When is the sunrise / sunset in December in Harleysville?
How long on average sun shines in December in Harleysville?
What are the months with the lowest UV index in Harleysville?
How high is the UV index in December in Harleysville?
Average temperature in December
Harleysville, PA
- Average high temperature in December: 41.5°F
The warmest month (with the highest average high temperature) is July (84.6°F).
The month with the lowest average high temperature is January (35.2°F).
- Average low temperature in December: 30.4°F
The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (22.8°F).
Average pressure in December
Harleysville, PA
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Harleysville, PA
- Average wind speed in December: 7.5mph
The windiest month (with the highest average wind speed) is March (8.1mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in December
Harleysville, PA
- Average humidity in December: 80%
The month with the highest relative humidity is February (81%).
The months with the lowest relative humidity are April and July (75%).
Average rainfall in December
Harleysville, PA
- Average rainfall in December: 1.34"
The wettest month (with the highest rainfall) is July (1.97").
The driest month (with the least rainfall) is January (0.87").
Average rainfall days in December
Harleysville, PA
- Average rainfall days in December: 8 days
The month with the highest number of rainy days is July (15.7 days).
The month with the least rainy days is January (5.7 days).
Average snowfall in December
Harleysville, PA
- Average snowfall in December: 1.34"
The month with the highest snowfall is March (1.46").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Harleysville, PA
- Average snowfall days in December: 2 days
The month with the highest number of snowfall days is February (5.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Harleysville, PA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
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 30min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in December
Harleysville, PA
- Average sunshine days in December: 20.1 days
The month with the most sunshine days is November (21.4 days).
The month with the least sunshine days is July (12.8 days).
Average UV index in December
Harleysville, PA
- 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, March, November and December (UV index 2).
Average cloud cover in December
Harleysville, PA
- 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
Harleysville, PA
- 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).
Harleysville, Pennsylvania, USA
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