December weather forecast
Saint John, UT

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Weather in December

The first month of the winter, December, is also a wintry month in Saint John, Utah, with temperature in the range of an average high of 32.9°F (0.5°C) and an average low of 19.8°F (-6.8°C).

Temperature

December comes with a drop in the average high-temperature, falling from November's chilly 45.5°F (7.5°C) to a cold 32.9°F (0.5°C). Saint John records an average nighttime low-temperature of 19.8°F (-6.8°C) throughout December.

Humidity

In December, the average relative humidity is 79%.

Rainfall

In December, the rain falls for 8.5 days. Throughout December, 1.77" (45mm) of precipitation is accumulated. Throughout the year, there are 120.7 rainfall days, and 18.39" (467mm) of precipitation is accumulated.

Snowfall

January through May, September through December are months with snowfall. The months with the most snowfall are January and December, with an average 12.99" (330mm) of accumulated snow.

Daylight

December has the shortest days of the year, with an average of 9h and 24min of daylight.
On the first day of December in Saint John, sunrise is at 7:34 am and sunset at 5:04 pm. On the last day of the month, sunrise is at 7:52 am and sunset at 5:13 pm MST.

Sunshine

In December, the average sunshine is 5.6h.

UV index

With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index reading of 2, and below, represents a low health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: An average UV index of 1 in December transforms into this advice:
Prolonged sun exposure should always be prevented in babies, children, and those with sensitive skin. Avoiding the Sun during its peak radiation time around midday is a healthy practice. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Updated: Jul 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

An average high-temperature, in December, in Saint John, is 32.9°F (0.5°C) and the average low-temperature is 19.8°F (-6.8°C).

What is the average humidity in December?

In December, the average relative humidity is 79%.

How much does it rain in December?

In Saint John, in December, it is raining for 8.5 days, with typically 1.77" (45mm) of accumulated precipitation.

When does it snow the most?

The months with the most snowfall are January and December, with an average 12.99" (330mm) of accumulated snow.

How many days does it snow in December?

In December, it is snowing for 14.5 days. Throughout December, 12.99" (330mm) of snow is accumulated.

What is the month with the shortest days?

December has the shortest days of the year in Saint John, Utah, with an average of 9h and 24min of daylight.

What is the average length of the day in December?

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

What time are sunrise and sunset in December?

On the first day of December, sunrise is at 7:34 am and sunset at 5:04 pm. On the last day of the month, sunrise is at 7:52 am and sunset at 5:13 pm MST.

How many hours of sunshine does Saint John have in December?

In December, the average sunshine duration is 5.6h.

When is 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?

In Saint John, the average daily maximum UV index in December is 1. A UV Index reading 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
Saint John, UT

Average temperature in December - Saint John, UT
  • Average high temperature in December: 32.9°F

The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (32.4°F).

  • Average low temperature in December: 19.8°F

The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).

Average pressure in December
Saint John, UT

Average pressure in December - Saint John, UT
  • Average pressure in December: 30.21"Hg

The month with the highest atmospheric pressure is January (30.27"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).

Average wind speed in December
Saint John, UT

Average wind speed in December - Saint John, UT
  • Average wind speed in December: 6.2mph

The windiest month (with the highest average wind speed) is April (7.7mph).
The calmest month (with the lowest average wind speed) is January (5.3mph).

Average humidity in December
Saint John, UT

Average humidity in December - Saint John, UT
  • Average humidity in December: 79%

The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is July (33%).

Average rainfall in December
Saint John, UT

Average rainfall in December - Saint John, UT
  • Average rainfall in December: 1.77"

The wettest month (with the highest rainfall) is April (2.09").
The driest month (with the least rainfall) is June (0.79").

Average rainfall days in December
Saint John, UT

Average rainfall days in December - Saint John, UT
  • Average rainfall days in December: 8.5 days

The month with the highest number of rainy days is May (13.3 days).
The month with the least rainy days is November (6.5 days).

Average snowfall in December
Saint John, UT

Average snowfall in December - Saint John, UT
  • Average snowfall in December: 12.99"

The months with the highest snowfall are January and December (12.99").
The months with the least snowfall are June, July and August (0").

Average snowfall days in December
Saint John, UT

Average snowfall days in December - Saint John, UT
  • Average snowfall days in December: 14.5 days

The month with the highest number of snowfall days is January (14.7 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in December /
Average sunshine in December
Saint John, UT

Average daylight in December / Average sunshine in December - Saint John, UT
  • 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 4min

The month with the most sunshine is August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 5h and 12min).

Average sunshine days in December
Saint John, UT

Average sunshine days in December - Saint John, UT
  • Average sunshine days in December: 14.1 days

The month with the most sunshine days is October (20.1 days).
The month with the least sunshine days is February (11.6 days).

Average UV index in December
Saint John, UT

Average UV index in December - Saint John, UT
  • 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
Saint John, UT

Average cloud cover in December - Saint John, UT
  • Average cloud cover in December: 42

The month with the most cloud cover is January (Cloud cover 43).
The month with the least cloud cover is August (Cloud cover 12).

Average visibility in December
Saint John, UT

Average visibility in December - Saint John, UT
  • Average visibility in December: 5mi

The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).

Saint John, Utah, USA

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