December weather forecastMill Creek, PA
December
Weather in December
The first month of the winter, December, is also a wintry month in Mill Creek, Pennsylvania, with an average temperature fluctuating between 27.5°F (-2.5°C) and 38.8°F (3.8°C).Temperature
The shift from November to December involves a decrease in the average high-temperature, dropping from a chilly 48.4°F (9.1°C) to a wintry 38.8°F (3.8°C). Nighttime temperatures in December average to a freezing cold 27.5°F (-2.5°C).Humidity
The average relative humidity in December is 81%.Rainfall
In Mill Creek, in December, during 10.9 rainfall days, 2.36" (60mm) of precipitation is typically accumulated. In Mill Creek, during the entire year, the rain falls for 164.3 days and collects up to 28.19" (716mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In December, it is snowing for 7.7 days. Throughout December, 2.56" (65mm) of snow is accumulated. In Mill Creek, during the entire year, snow falls for 40.6 days and aggregates up to 17.91" (455mm) of snow.Daylight
The month with the shortest days in Mill Creek is December, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:16 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:34 am and sunset at 4:55 pm EST.
Sunshine
The average sunshine in December is 4.3h.UV index
January through March, October through 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 threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: In December, the maximum UV index of 2 suggests this advice:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Mill Creek, PA
- Average high temperature in December: 38.8°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (32.9°F).
- Average low temperature in December: 27.5°F
The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).
Average pressure in December
Mill Creek, PA
- 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
Mill Creek, PA
- Average wind speed in December: 7.1mph
The windiest month (with the highest average wind speed) is January (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).
Average humidity in December
Mill Creek, PA
- Average humidity in December: 81%
The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is July (75%).
Average rainfall in December
Mill Creek, PA
- Average rainfall in December: 2.36"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is September (1.85").
Average rainfall days in December
Mill Creek, PA
- Average rainfall days in December: 10.9 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (9.5 days).
Average snowfall in December
Mill Creek, PA
- Average snowfall in December: 2.56"
The month with the highest snowfall is January (5.24").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Mill Creek, PA
- Average snowfall days in December: 7.7 days
The month with the highest number of snowfall days is January (12.2 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
Mill Creek, PA
- Average daylight in December: 9h and 18min
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 18min).
- Average sunshine in December: 4h and 18min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in December
Mill Creek, PA
- Average sunshine days in December: 14.2 days
The month with the most sunshine days is November (16.7 days).
The month with the least sunshine days is May (10.7 days).
Average UV index in December
Mill Creek, PA
- Average UV index in December: 2
The months with the highest UV index are May and June (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in December
Mill Creek, PA
- Average cloud cover in December: 55
The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are July and August (Cloud cover 34).
Average visibility in December
Mill Creek, PA
- Average visibility in December: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).





