December weather forecastHarleysville, PA
December
Weather in December
December, the first month of the winter in Harleysville, is also a wintry month, with an average temperature varying between 41.5°F (5.3°C) and 30.4°F (-0.9°C).Temperature
December implies a gentle temperature shift, with average high-temperatures reducing from November's cool 50.9°F (10.5°C) to an icy 41.5°F (5.3°C). Harleysville, in the month of December, anticipates a consistent average low-temperature of 30.4°F (-0.9°C).Humidity
In Harleysville, 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. In Harleysville, during the entire year, the rain falls for 128.6 days and collects up to 15.16" (385mm) of precipitation.Snowfall
Months with snowfall are January through May, November and December. In Harleysville, Pennsylvania, in December, snow falls for 2 days, with typically accumulated 1.34" (34mm) of snow. In Harleysville, during the entire year, snow falls for 17 days and aggregates up to 5.43" (138mm) 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 the month, sunrise is at 7:05 am and sunset at 4:36 pm. On the last day of December, sunrise is at 7:24 am and sunset at 4:45 pm EST.
Sunshine
In December, the average sunshine is 4.8h.UV index
January through March, 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 low health risk from exposure to the Sun's UV radiation for the ordinary person.Note: An average UV index of 2 in December transforms into this advice:
While most individuals can withstand prolonged sun exposure, it is imperative that babies, children, and those with sensitive skin always be shielded. The Sun's radiation is especially intense around midday; try to stay in shade during this period. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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 24min
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 48min
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).
