December weather forecast
West Mifflin, PA

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Weather in December

December, the first month of the winter in West Mifflin, is still a cold month, with temperature in the range of an average low of 28.4°F (-2°C) and an average high of 39.6°F (4.2°C).

Temperature

Observing a mild shift, the average high-temperature during December reduces from November's frosty 49.3°F (9.6°C) to a wintry 39.6°F (4.2°C). During December, West Mifflin observes a consistent average nighttime temperature of 28.4°F (-2°C).

Humidity

In West Mifflin, the average relative humidity in December is 83%.

Rainfall

In West Mifflin, in December, it is raining for 8.5 days, with typically 0.79" (20mm) of accumulated precipitation. In West Mifflin, during the entire year, the rain falls for 128 days and collects up to 10.2" (259mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In West Mifflin, in December, snow falls for 10.1 days, with typically accumulated 1.26" (32mm) of snow. Throughout the year, in West Mifflin, Pennsylvania, there are 50 snowfall days, and 6.69" (170mm) of snow is accumulated.

Daylight

With an average of 9h and 24min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:23 am and sunset at 4:53 pm. On the last day of December, sunrise is at 7:42 am and sunset at 5:03 pm EST.

Sunshine

In December, the average sunshine is 3.4h.

UV index

The month with the lowest UV index is December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV rays for average individuals.
Note: An average maximum UV index of 1 in December leads to these recommendations:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. To cut down UV radiation exposure by about half, sport a wide-brim hat. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.

Frequently asked questions

How cold does it get in December?

In West Mifflin, in December, the average high-temperature is 39.6°F (4.2°C), and the average low-temperature is 28.4°F (-2°C). In August, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, is evaluated at 87.8°F (31°C).

What is the average humidity in December?

In West Mifflin, the average relative humidity in December is 83%.

How many days does it rain in December?

In West Mifflin, in December, during 8.5 rainfall days, 0.79" (20mm) of precipitation is typically accumulated.

How many days does it snow in December?

In West Mifflin, in December, during 10.1 snowfall days, 1.26" (32mm) of snow is typically accumulated.

What is the month with the shortest days?

With an average of 9h and 24min of daylight, December has the shortest days of the year.

What is the average length of the day in December?

In December, the average day length is 9h and 21min.

When are sunrise and sunset in December?

On the first day of December in West Mifflin, sunrise is at 7:23 am and sunset at 4:53 pm. On the last day of the month, sunrise is at 7:42 am and sunset at 5:03 pm EST.

How long on average sun shines in December?

In West Mifflin, the average sunshine duration in December is 3.4h.

What is the month with the lowest UV index?

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

How high is the UV index 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
West Mifflin, PA

Average temperature in December - West Mifflin, PA
  • Average high temperature in December: 39.6°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 (33.4°F).

  • Average low temperature in December: 28.4°F

The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).

Average pressure in December
West Mifflin, PA

Average pressure in December - West Mifflin, 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 (29.95"Hg).

Average wind speed in December
West Mifflin, PA

Average wind speed in December - West Mifflin, PA
  • Average wind speed in December: 7.3mph

The windiest month (with the highest average wind speed) is January (8mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).

Average humidity in December
West Mifflin, PA

Average humidity in December - West Mifflin, PA
  • Average humidity in December: 83%

The month with the highest relative humidity is February (85%).
The month with the lowest relative humidity is August (74%).

Average rainfall in December
West Mifflin, PA

Average rainfall in December - West Mifflin, PA
  • Average rainfall in December: 0.79"

The wettest month (with the highest rainfall) is May (1.26").
The driest months (with the least rainfall) are September and November (0.55").

Average rainfall days in December
West Mifflin, PA

Average rainfall days in December - West Mifflin, PA
  • Average rainfall days in December: 8.5 days

The month with the highest number of rainy days is May (15 days).
The month with the least rainy days is February (7.1 days).

Average snowfall in December
West Mifflin, PA

Average snowfall in December - West Mifflin, PA
  • Average snowfall in December: 1.26"

The months with the highest snowfall are January and February (1.65").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
West Mifflin, PA

Average snowfall days in December - West Mifflin, PA
  • Average snowfall days in December: 10.1 days

The month with the highest number of snowfall days is January (14.4 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
West Mifflin, PA

Average daylight in December / Average sunshine in December - West Mifflin, 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: 3h and 2min

The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).

Average sunshine days in December
West Mifflin, PA

Average sunshine days in December - West Mifflin, PA
  • Average sunshine days in December: 16.5 days

The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is May (12.3 days).

Average UV index in December
West Mifflin, PA

Average UV index in December - West Mifflin, PA
  • Average UV index in December: 1

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

Average cloud cover in December
West Mifflin, PA

Average cloud cover in December - West Mifflin, PA
  • Average cloud cover in December: 65

The month with the most cloud cover is January (Cloud cover 69).
The month with the least cloud cover is August (Cloud cover 33).

Average visibility in December
West Mifflin, PA

Average visibility in December - West Mifflin, PA
  • Average visibility in December: 5mi

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

West Mifflin, Pennsylvania, USA

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