December weather forecast
Mount Morris, PA

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Weather in December

December, the first month of the winter in Mount Morris, is also an icy month, with temperature in the range of an average low of 29.3°F (-1.5°C) and an average high of 40.6°F (4.8°C).

Temperature

The commencement of December indicates a shift in the average high-temperature, receding from November's fresh 50°F (10°C) to a cold 40.6°F (4.8°C). Mount Morris observes an average low-temperature of 29.3°F (-1.5°C) during December.

Humidity

In December, the average relative humidity is 83%.

Rainfall

In Mount Morris, in December, it is raining for 13 days, with typically 3.19" (81mm) of accumulated precipitation. Throughout the year, there are 187.8 rainfall days, and 36.46" (926mm) of precipitation is accumulated.

Snowfall

January through May, October through December are months with snowfall. In Mount Morris, in December, snow falls for 13.1 days, with typically accumulated 6.14" (156mm) of snow. Throughout the year, there are 63.1 snowfall days, and 32.32" (821mm) 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 4:56 pm. On the last day of December, sunrise is at 7:41 am and sunset at 5:06 pm EST.

Sunshine

In December, the average sunshine is 3.8h.

UV index

With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: A typical high UV index of 1 in December suggests the following recommendations:
Children, infants, and individuals with sensitive skin should be constantly protected from extended sun exposure. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Updated: Aug 11, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold does it get in December?

In Mount Morris, 40.6°F (4.8°C) is the average high-temperature and 29.3°F (-1.5°C) is the average low-temperature during December. In August, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is appraised at 87.8°F (31°C).

What is the average humidity in December?

In December, the average relative humidity is 83%.

How much does it rain in December?

In December, the rain falls for 13 days. Throughout December, 3.19" (81mm) of precipitation is accumulated.

How many days does it snow in December?

In December, it is snowing for 13.1 days. Throughout December, 6.14" (156mm) of snow is accumulated.

What is the month with the shortest days?

The month with the shortest days 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 25min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 7:22 am and sunset at 4:56 pm. On the last day of the month, sunrise is at 7:41 am and sunset at 5:06 pm EST.

How long on average sun shines in December?

In December, the average sunshine duration is 3.8h.

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.

What is the UV index reading in December?

In Mount Morris, the average daily maximum UV index in December is 1. A UV Index of 2, and less, symbolizes 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
Mount Morris, PA

Average temperature in December - Mount Morris, PA
  • Average high temperature in December: 40.6°F

The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (34.5°F).

  • Average low temperature in December: 29.3°F

The month with the highest average low temperature is July (60.6°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).

Average pressure in December
Mount Morris, PA

Average pressure in December - Mount Morris, PA
  • Average pressure in December: 30.12"Hg

The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).

Average wind speed in December
Mount Morris, PA

Average wind speed in December - Mount Morris, PA
  • Average wind speed in December: 6.8mph

The windiest month (with the highest average wind speed) is January (7.4mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).

Average humidity in December
Mount Morris, PA

Average humidity in December - Mount Morris, PA
  • Average humidity in December: 83%

The months with the highest relative humidity are January and February (84%).
The months with the lowest relative humidity are July and August (77%).

Average rainfall in December
Mount Morris, PA

Average rainfall in December - Mount Morris, PA
  • Average rainfall in December: 3.19"

The wettest month (with the highest rainfall) is May (4.02").
The driest month (with the least rainfall) is September (2.17").

Average rainfall days in December
Mount Morris, PA

Average rainfall days in December - Mount Morris, PA
  • Average rainfall days in December: 13 days

The month with the highest number of rainy days is May (20.5 days).
The month with the least rainy days is January (11.1 days).

Average snowfall in December
Mount Morris, PA

Average snowfall in December - Mount Morris, PA
  • Average snowfall in December: 6.14"

The month with the highest snowfall is February (7.76").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Mount Morris, PA

Average snowfall days in December - Mount Morris, PA
  • Average snowfall days in December: 13.1 days

The month with the highest number of snowfall days is January (17 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Mount Morris, PA

Average daylight in December / Average sunshine in December - Mount Morris, PA
  • Average daylight in December: 9h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in December: 3h and 5min

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

Average sunshine days in December
Mount Morris, PA

Average sunshine days in December - Mount Morris, PA
  • Average sunshine days in December: 10 days

The month with the most sunshine days is November (13.5 days).
The month with the least sunshine days is January (6.7 days).

Average UV index in December
Mount Morris, PA

Average UV index in December - Mount Morris, PA
  • Average UV index in December: 1

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

Average cloud cover in December
Mount Morris, PA

Average cloud cover in December - Mount Morris, PA
  • Average cloud cover in December: 63

The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 35).

Average visibility in December
Mount Morris, PA

Average visibility in December - Mount Morris, PA
  • Average visibility in December: 5mi

The months with the highest visibility are March, April, May, June, July, August, September, October, November and December (5mi).
The months with the lowest visibility are January and February (4mi).

Mount Morris, Pennsylvania, USA

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