December weather forecast
Upper Darby, PA

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Weather in December

December, the first month of the winter in Upper Darby, is still a chilly month, with temperature in the range of an average high of 44.1°F (6.7°C) and an average low of 32.7°F (0.4°C).

Temperature

December ushers in a minute temperature change, with average high-temperatures reducing from November's fresh 52.7°F (11.5°C) to a chilly 44.1°F (6.7°C). During the nights in December, Upper Darby observes an average low-temperature of 32.7°F (0.4°C).

Humidity

February, October and December, with an average relative humidity of 77%, are the most humid months.

Rainfall

In Upper Darby, in December, it is raining for 9.6 days, with typically 2.4" (61mm) of accumulated precipitation. In Upper Darby, during the entire year, the rain falls for 142 days and collects up to 24.41" (620mm) of precipitation.

Snowfall

January through April, November and December are months with snowfall. In Upper Darby, in December, snow falls for 1.5 days, with typically accumulated 0.75" (19mm) of snow. In Upper Darby, Pennsylvania, during the entire year, snow falls for 11.3 days and aggregates up to 6.18" (157mm) 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 December, sunrise is at 7:04 am and sunset at 4:36 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:46 pm EST.

Sunshine

In December, the average sunshine is 5.1h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV radiation for the average person.
Note: In December, the average maximum UV index of 2 translates into the following recommendations:
Many can withstand an hour in the sun without burning, yet children must always have protection against sunlight. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Updated: Jul 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is December cold in Upper Darby?

In December, in Upper Darby, the average high-temperature is 44.1°F (6.7°C), and the average low-temperature is 32.7°F (0.4°C). In August, the average heat index (a.k.a. 'feels like', 'real feel'), which factors the actual air temperature with the relative humidity, is appraised at 91.4°F (33°C).

What is the most humid month?

The months with the highest humidity are February, October and December, with an average relative humidity of 77%.

What is the average humidity in December?

The average relative humidity in December is 77%.

How much does it rain in December?

In Upper Darby, in December, during 9.6 rainfall days, 2.4" (61mm) of precipitation is typically accumulated.

How many days does it snow in December?

In December, it is snowing for 1.5 days. Throughout December, 0.75" (19mm) of snow is accumulated.

What is the month with the shortest days?

The month with the shortest days in Upper Darby is December, with an average of 9h and 24min of daylight.

What is the average length of the day in December?

In December, the average day length is 9h and 23min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:04 am and sunset at 4:36 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:46 pm EST.

How long on average sun shines in December?

In Upper Darby, the average sunshine duration in December is 5.1h.

When is the lowest UV index?

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.

How high is the UV index in December?

In Upper Darby, the average daily maximum UV index in December is 2. A UV Index estimate of 2, and below, represents a minimal hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Upper Darby, PA

Average temperature in December - Upper Darby, PA
  • Average high temperature in December: 44.1°F

The warmest month (with the highest average high temperature) is July (86°F).
The month with the lowest average high temperature is January (37.4°F).

  • Average low temperature in December: 32.7°F

The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).

Average pressure in December
Upper Darby, PA

Average pressure in December - Upper Darby, 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
Upper Darby, PA

Average wind speed in December - Upper Darby, PA
  • Average wind speed in December: 7.8mph

The windiest months (with the highest average wind speed) are February, March and April (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).

Average humidity in December
Upper Darby, PA

Average humidity in December - Upper Darby, PA
  • Average humidity in December: 77%

The months with the highest relative humidity are February, October and December (77%).
The month with the lowest relative humidity is April (71%).

Average rainfall in December
Upper Darby, PA

Average rainfall in December - Upper Darby, PA
  • Average rainfall in December: 2.4"

The wettest month (with the highest rainfall) is August (2.95").
The driest month (with the least rainfall) is January (1.46").

Average rainfall days in December
Upper Darby, PA

Average rainfall days in December - Upper Darby, PA
  • Average rainfall days in December: 9.6 days

The month with the highest number of rainy days is July (16.9 days).
The month with the least rainy days is January (6.6 days).

Average snowfall in December
Upper Darby, PA

Average snowfall in December - Upper Darby, PA
  • Average snowfall in December: 0.75"

The month with the highest snowfall is March (2.05").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December
Upper Darby, PA

Average snowfall days in December - Upper Darby, PA
  • Average snowfall days in December: 1.5 days

The month with the highest number of snowfall days is January (3.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in December /
Average sunshine in December
Upper Darby, PA

Average daylight in December / Average sunshine in December - Upper Darby, 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: 5h and 1min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).

Average sunshine days in December
Upper Darby, PA

Average sunshine days in December - Upper Darby, PA
  • Average sunshine days in December: 19.7 days

The month with the most sunshine days is January (20.8 days).
The month with the least sunshine days is July (12.1 days).

Average UV index in December
Upper Darby, PA

Average UV index in December - Upper Darby, 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, November and December (UV index 2).

Average cloud cover in December
Upper Darby, PA

Average cloud cover in December - Upper Darby, PA
  • Average cloud cover in December: 46

The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 30).

Average visibility in December
Upper Darby, PA

Average visibility in December - Upper Darby, PA
  • Average visibility in December: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Upper Darby, Pennsylvania, USA

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