December weather forecast
Swarthmore, PA

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Weather in December

December, the first month of the winter in Swarthmore, is still a chilly month, with an average temperature fluctuating between 32.9°F (0.5°C) and 44.1°F (6.7°C).

Temperature

As December commences, the average high-temperature subtly reduces, transitioning from a fresh 52.7°F (11.5°C) in November to a chilly 44.1°F (6.7°C). Swarthmore, during the nights of December, experiences an average temperature drop to a wintry 32.9°F (0.5°C).

Humidity

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

Rainfall

In Swarthmore, Pennsylvania, during December, the rain falls for 8.7 days and regularly aggregates up to 2.32" (59mm) of precipitation. In Swarthmore, during the entire year, the rain falls for 148.4 days and collects up to 25.94" (659mm) of precipitation.

Snowfall

Months with snowfall are January through May, November and December. In Swarthmore, in December, during 1.5 snowfall days, 0.91" (23mm) of snow is typically accumulated. Throughout the year, there are 12.6 snowfall days, and 7.28" (185mm) of snow is accumulated.

Daylight

The month with the shortest days in Swarthmore is December, with an average of 9h and 24min of daylight.
On the first day of the month, sunrise is at 7:04 am and sunset at 4:36 pm. On the last day of December, sunrise is at 7:22 am and sunset at 4:46 pm EST.

Sunshine

In December, the average sunshine in Swarthmore is 5.1h.

UV index

The months with the lowest UV index in Swarthmore are January, February, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: The maximum daily UV index of 2 in December interprets into the following recommendations:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. To protect against the Sun's most potent rays, avoid direct exposure around midday. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
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Frequently asked questions

Is December cold in Swarthmore?

The average high-temperature, in December, in Swarthmore, is 44.1°F (6.7°C), while the average low-temperature is 32.9°F (0.5°C). In August, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which combines air temperature and relative humidity, is estimated at 89.6°F (32°C).

What are the most humid months in Swarthmore?

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

What is the average humidity in December in Swarthmore?

In Swarthmore, the average relative humidity in December is 77%.

How much does it rain in Swarthmore in December?

In December, in Swarthmore, the rain falls for 8.7 days. Throughout December, 2.32" (59mm) of precipitation is accumulated.

How many days does it snow in December in Swarthmore?

In Swarthmore, in December, snow falls for 1.5 days, with typically accumulated 0.91" (23mm) of snow.

What is the month with the shortest days in Swarthmore?

December has the shortest days of the year in Swarthmore, Pennsylvania, with an average of 9h and 24min of daylight.

How many hours of daylight does Swarthmore have in December?

In December, the average day length is 9h and 24min.

When is the sunrise / sunset in December in Swarthmore?

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.

How long on average sun shines in December in Swarthmore?

The average sunshine duration in December is 5.1h.

What are the months with the lowest UV index in Swarthmore?

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

What is the UV index intensity in December in Swarthmore?

In Swarthmore, the average daily maximum UV index in December is 2. A UV Index estimate of 2, and below, represents a low health risk from unprotected exposure to 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
Swarthmore, PA

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

The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (37.4°F).

  • Average low temperature in December: 32.9°F

The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).

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Average pressure in December
Swarthmore, PA

Average pressure in December - Swarthmore, 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).

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Average wind speed in December
Swarthmore, PA

Average wind speed in December - Swarthmore, PA
  • Average wind speed in December: 7.9mph

The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).

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Average humidity in December
Swarthmore, PA

Average humidity in December - Swarthmore, 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%).

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Average rainfall in December
Swarthmore, PA

Average rainfall in December - Swarthmore, PA
  • Average rainfall in December: 2.32"

The wettest month (with the highest rainfall) is August (3.11").
The driest month (with the least rainfall) is January (1.61").

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Average rainfall days in December
Swarthmore, PA

Average rainfall days in December - Swarthmore, PA
  • Average rainfall days in December: 8.7 days

The month with the highest number of rainy days is July (17 days).
The month with the least rainy days is January (7.1 days).

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Average snowfall in December
Swarthmore, PA

Average snowfall in December - Swarthmore, PA
  • Average snowfall in December: 0.91"

The month with the highest snowfall is March (2.32").
The months with the least snowfall are June, July, August, September and October (0").

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Average snowfall days in December
Swarthmore, PA

Average snowfall days in December - Swarthmore, PA
  • Average snowfall days in December: 1.5 days

The month with the highest number of snowfall days is February (3.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

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Average daylight in December /
Average sunshine in December
Swarthmore, PA

Average daylight in December / Average sunshine in December - Swarthmore, 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).

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Average sunshine days in December
Swarthmore, PA

Average sunshine days in December - Swarthmore, PA
  • Average sunshine days in December: 20.5 days

The month with the most sunshine days is January (20.8 days).
The month with the least sunshine days is July (11.3 days).

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Average UV index in December
Swarthmore, PA

Average UV index in December - Swarthmore, 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).

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Average cloud cover in December
Swarthmore, PA

Average cloud cover in December - Swarthmore, PA
  • Average cloud cover in December: 45

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

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Average visibility in December
Swarthmore, PA

Average visibility in December - Swarthmore, 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).

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Swarthmore, Pennsylvania, USA

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