December weather forecast
Sewickley Heights, PA

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Weather in December

The first month of the winter, December, is also an icy month in Sewickley Heights, Pennsylvania, with an average temperature varying between 38.7°F (3.7°C) and 28°F (-2.2°C).

Temperature

The onset of December coincides with a reduction in the average high-temperature, falling from a chilly 48.6°F (9.2°C) in November to a wintry 38.7°F (3.7°C). Sewickley Heights's average low-temperature in the month of December is recorded at a subzero cold 28°F (-2.2°C).

Humidity

In December, the average relative humidity is 84%.

Rainfall

In Sewickley Heights, in December, it is raining for 6.6 days, with typically 0.67" (17mm) of accumulated precipitation. In Sewickley Heights, during the entire year, the rain falls for 104.1 days and collects up to 8.23" (209mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In Sewickley Heights, Pennsylvania, in December, snow falls for 6.4 days, with typically accumulated 0.67" (17mm) of snow. In Sewickley Heights, during the entire year, snow falls for 33.9 days and aggregates up to 4.37" (111mm) of snow.

Daylight

With an average of 9h and 18min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 7:25 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:44 am and sunset at 5:03 pm EST.

Sunshine

In December, the average sunshine is 3.2h.

UV index

With an average maximum UV index of 1, December is the month with the lowest UV index in Sewickley Heights. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for the average person.
Note: The daily high UV index of 1 in December translates into this advice:
Though the majority can handle prolonged sun exposure, it is crucial to always shield babies, children, and those with fair skin. The Sun's radiation is especially intense around midday; try to stay in shade during this period. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.
Updated: Aug 29, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is it cold during December?

The average high-temperature, in December, in Sewickley Heights, is 38.7°F (3.7°C), while the average low-temperature is 28°F (-2.2°C). The average heat index (a.k.a. 'real feel', 'apparent temperature'), which combines air temperature and relative humidity, in August is computed to be 87.8°F (31°C).

What is the average humidity in December?

In Sewickley Heights, the average relative humidity in December is 84%.

How many days does it rain in December?

In December, the rain falls for 6.6 days. Throughout December, 0.67" (17mm) of precipitation is accumulated.

How many days does it snow in December?

In Sewickley Heights, during December, snow falls for 6.4 days and regularly aggregates up to 0.67" (17mm) of snow.

What is the month with the shortest days?

With an average of 9h and 18min of daylight, December has the shortest days of the year in Sewickley Heights.

How many hours of daylight does Sewickley Heights have in December?

The average day length in December is 9h and 20min.

When is the sunrise / sunset in December in Sewickley Heights?

In December, on the first day of the month, sunrise is at 7:25 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:44 am and sunset at 5:03 pm EST.

How long on average sun shines in December?

In Sewickley Heights, the average sunshine duration in December is 3.2h.

When is the lowest UV index in Sewickley Heights?

December is the month with the lowest UV index, with an average maximum UV index of 1.

What is the UV index intensity in December?

The average daily maximum UV index in December is 1. A UV Index reading 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
Sewickley Heights, PA

Average temperature in December - Sewickley Heights, PA
  • Average high temperature in December: 38.7°F

The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (32.5°F).

  • Average low temperature in December: 28°F

The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).

Average pressure in December
Sewickley Heights, PA

Average pressure in December - Sewickley Heights, PA
  • Average pressure in December: 30.11"Hg

The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed in December
Sewickley Heights, PA

Average wind speed in December - Sewickley Heights, PA
  • Average wind speed in December: 7.3mph

The windiest month (with the highest average wind speed) is January (8mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).

Average humidity in December
Sewickley Heights, PA

Average humidity in December - Sewickley Heights, PA
  • Average humidity in December: 84%

The months with the highest relative humidity are January and February (85%).
The months with the lowest relative humidity are July and August (75%).

Average rainfall in December
Sewickley Heights, PA

Average rainfall in December - Sewickley Heights, PA
  • Average rainfall in December: 0.67"

The wettest months (with the highest rainfall) are June and July (0.91").
The driest months (with the least rainfall) are January and November (0.47").

Average rainfall days in December
Sewickley Heights, PA

Average rainfall days in December - Sewickley Heights, PA
  • Average rainfall days in December: 6.6 days

The month with the highest number of rainy days is May (12.7 days).
The month with the least rainy days is January (4.5 days).

Average snowfall in December
Sewickley Heights, PA

Average snowfall in December - Sewickley Heights, PA
  • Average snowfall in December: 0.67"

The month with the highest snowfall is February (1.18").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Sewickley Heights, PA

Average snowfall days in December - Sewickley Heights, PA
  • Average snowfall days in December: 6.4 days

The month with the highest number of snowfall days is February (9 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Sewickley Heights, PA

Average daylight in December / Average sunshine in December - Sewickley Heights, 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 18min).

  • Average sunshine in December: 3h and 1min

The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 2h and 54min).

Average sunshine days in December
Sewickley Heights, PA

Average sunshine days in December - Sewickley Heights, PA
  • Average sunshine days in December: 20.5 days

The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is May (14.7 days).

Average UV index in December
Sewickley Heights, PA

Average UV index in December - Sewickley Heights, PA
  • Average UV index in December: 1

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in December
Sewickley Heights, PA

Average cloud cover in December - Sewickley Heights, PA
  • Average cloud cover in December: 67

The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is August (Cloud cover 34).

Average visibility in December
Sewickley Heights, PA

Average visibility in December - Sewickley Heights, PA
  • Average visibility in December: 5mi

The months with the highest visibility are April, June, August and November (6mi).
The months with the lowest visibility are January, February, March, May, July, September, October and December (5mi).

Sewickley Heights, Pennsylvania, USA

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