December weather forecast
Irwin, PA

Share

Weather in December

December, the first month of the winter in Irwin, is also an icy month, with temperature in the range of an average high of 39.6°F (4.2°C) and an average low of 28.6°F (-1.9°C).

Temperature

A shift in Irwin's weather is observed as November turns into December, with the average high temperature reducing from a chilly 49.5°F (9.7°C) to a cold 39.6°F (4.2°C). In the month of December, Irwin records a consistent average low-temperature of 28.6°F (-1.9°C).

Humidity

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

Rainfall

In Irwin, in December, during 11.2 rainfall days, 1.46" (37mm) of precipitation is typically accumulated. Throughout the year, in Irwin, there are 161.9 rainfall days, and 19.29" (490mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through April, October through December. In December, it is snowing for 10.1 days. Throughout December, 1.69" (43mm) of snow is accumulated. Throughout the year, there are 49.2 snowfall days, and 8.62" (219mm) 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 7:22 am and sunset at 4:53 pm. On the last day of December, in Irwin, sunrise is at 7:41 am and sunset at 5:02 pm EST.

Sunshine

In Irwin, the average sunshine in December is 3.5h.

UV index

December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a low health risk from exposure to the Sun's UV radiation for average individuals.
Note: The average daily UV index of 1 in December transforms into the following instructions:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. Enhance your sun protection with tightly woven, yet airy clothing. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.

Frequently asked questions

How cold does it get in Irwin in December?

The high-temperature, in December, in Irwin, is 39.6°F (4.2°C), while the low-temperature averages to 28.6°F (-1.9°C). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which factors the actual air temperature with the relative humidity, in August is estimated at 86°F (30°C).

What is the average humidity in December?

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

How much does it rain in December?

In December, the rain falls for 11.2 days. Throughout December, 1.46" (37mm) of precipitation is accumulated.

How many days does it snow in December in Irwin?

In December, it is snowing for 10.1 days. Throughout December, 1.69" (43mm) of snow is 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.

How many hours of daylight does Irwin have in December?

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

What time are sunrise and sunset in December?

On the first day of December in Irwin, sunrise is at 7:22 am and sunset at 4:53 pm. On the last day of the month, sunrise is at 7:41 am and sunset at 5:02 pm EST.

How many hours of sunshine does Irwin have in December?

The average sunshine duration in December is 3.5h.

When is the lowest UV index in Irwin?

With an average maximum UV index of 1, December is the month with the lowest UV index in Irwin, Pennsylvania.

What is the UV index reading in December?

In December, the average daily maximum UV index is 1. A UV Index estimate of 2, and below, represents a low health risk from unsafe exposure to Sun's UV rays.
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
Irwin, PA

Average temperature in December - Irwin, PA
  • Average high temperature in December: 39.6°F

The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (33.6°F).

  • Average low temperature in December: 28.6°F

The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).

Average pressure in December
Irwin, PA

Average pressure in December - Irwin, 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
Irwin, PA

Average wind speed in December - Irwin, PA
  • Average wind speed in December: 7.4mph

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
Irwin, PA

Average humidity in December - Irwin, PA
  • Average humidity in December: 84%

The month with the highest relative humidity is February (85%).
The months with the lowest relative humidity are April, July and August (76%).

Average rainfall in December
Irwin, PA

Average rainfall in December - Irwin, PA
  • Average rainfall in December: 1.46"

The wettest month (with the highest rainfall) is May (2.28").
The driest months (with the least rainfall) are January and November (1.14").

Average rainfall days in December
Irwin, PA

Average rainfall days in December - Irwin, PA
  • Average rainfall days in December: 11.2 days

The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is January (9.1 days).

Average snowfall in December
Irwin, PA

Average snowfall in December - Irwin, PA
  • Average snowfall in December: 1.69"

The month with the highest snowfall is January (2.13").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Irwin, PA

Average snowfall days in December - Irwin, PA
  • Average snowfall days in December: 10.1 days

The month with the highest number of snowfall days is January (14.2 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
Irwin, PA

Average daylight in December / Average sunshine in December - Irwin, 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 3min

The month with the most sunshine is August (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).

Average sunshine days in December
Irwin, PA

Average sunshine days in December - Irwin, PA
  • Average sunshine days in December: 12.1 days

The month with the most sunshine days is November (17 days).
The month with the least sunshine days is February (9 days).

Average UV index in December
Irwin, PA

Average UV index in December - Irwin, 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
Irwin, PA

Average cloud cover in December - Irwin, PA
  • Average cloud cover in December: 64

The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 32).

Average visibility in December
Irwin, PA

Average visibility in December - Irwin, 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).

Irwin, Pennsylvania, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location