St. John's
Canada
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
St. John's, Canada

The first month of the winter, December, is still a cold month in St. John's, with temperature in the range of an average low of -4.7°C (23.5°F) and an average high of 1.8°C (35.2°F).

Temperature

In St. John's, the average high-temperature slightly decreases, from a chilly 6.4°C (43.5°F) in November, to a cold 1.8°C (35.2°F). In St. John's, in December, the average low-temperature is -4.7°C (23.5°F).

Rainfall

In December, in St. John's, Canada, the rain falls for 12.7 days. Throughout December, 102.9mm (4.1") of precipitation is accumulated. In St. John's, during the entire year, the rain falls for 162.7 days and collects up to 1206.5mm (47.5") of precipitation.

Snowfall

Months with snowfall in St. John's are January through June, October through December. In St. John's, during 14.6 snowfall days, 634mm (25") of snow is typically accumulated. In St. John's, during the entire year, snow falls for 79 days, and aggregates up to 3349.4mm (131.9") of snow.

Sea temperature

In December, the average sea temperature in St. John's is 2.6°C (36.7°F).
Note: For swimming, this is considered very dangerous and immediately life-threatening. Total loss of breathing control instantly occurs, and clear thinking becomes almost impossible. A specialized swimsuit is obligatory to minimize thermal loss.

Daylight

With an average of 8.5h of daylight, December has the shortest days of the year in St. John's.

Sunshine

The month with the least sunshine in St. John's is December, with an average of 2h of sunshine.

UV index

Months with the lowest UV index in St. John's are January, November and December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low threat to health from unsafe exposure to the UV radiation for ordinary individuals.
Note: In December, the average maximum UV index of 1 translate into the following recommendations:
Extended sun exposure is not an issue for the majority. Children, infants, and fair-skinned individuals always need to be protected. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.

What is the temperature in December in St. John's?

In St. John's, Canada, in December, the average high-temperature is 1.8°C (35.2°F), and the average low-temperature is -4.7°C (23.5°F).

How many days does it rain in December in St. John's?

In St. John's, during December, the rain falls for 12.7 days and regularly aggregates up to 102.9mm (4.1") of precipitation.

How much does it snow in St. John's in December?

In St. John's, Canada, in December, snow falls for 14.6 days, with typically accumulated 634mm (25") of snow.

How cold is the water in December in St. John's?

In St. John's, in December, the average water temperature is 2.6°C (36.7°F). For swimming, this is considered extremely cold, dangerous, and life-threatening. Unless suitably protected with insulated waterproof clothing, hypothermia quickly occurs.

What is the month with the shortest days in St. John's?

The month with the shortest days in St. John's, Canada, is December, with an average of 8.5h of daylight.

What is the average length of the day in December in St. John's?

The average length of the day in December in St. John's is 8.5h.

What is the month with the least sunshine in St. John's?

December has the least sunshine of the year in St. John's, Canada, with an average of 2h of sunshine.

How long on average sun shines in December in St. John's?

The average sunshine in December in St. John's is 2h.

What are the months with the lowest UV index in St. John's?

Months with the lowest UV index in St. John's are January, November and December, with an average maximum UV index of 1.

What is the UV index intensity in December in St. John's?

In St. John's, the average daily maximum UV index in December is 1. A UV Index of 2, and less, symbolizes a minimal hazard to health from the exposure to the Sun's UV radiation.
Average temperature in December - St. John
  • Average high temperature in December: 1.8°C

The warmest month (with the highest average high temperature) is July (20.7°C).
The month with the lowest average high temperature is February (-1.1°C).

  • Average low temperature in December: -4.7°C

The month with the highest average low temperature is August (11.6°C).
The coldest month (with the lowest average low temperature) is February (-8.6°C).

Average rainfall in December - St. John
  • Average rainfall in December: 102.9mm

The wettest month (with the highest rainfall) is October (153.7mm).
The driest month (with the lowest rainfall) is February (61.6mm).

Average rainfall days in December - St. John
  • Average rainfall days in December: 12.7 days

The month with the highest number of rainy days is October (18.1 days).
The month with the lowest number of rainy days is February (8.6 days).

Average snowfall in December - St. John
  • Average snowfall in December: 634mm

The month with the highest snowfall is January (887mm).
Months with the lowest snowfall are July, August and September (0mm).

Average snowfall days in December - St. John
  • Average snowfall days in December: 14.6 days

The month with the highest number of snowfall days is January (18.3 days).
Months with the lowest number of snowfall days are July, August and September (0 days).

Average sea temperature in December - St. John
  • Average sea temperature in December: 2.6°C

The best month for swimming (with the highest average sea temperature) is August (13.9°C).
The coldest month (with the lowest average sea temperature) is March (-0.4°C).

Average daylight in December / Average sunshine in December - St. John
  • Average daylight in December: 8.5h

The month with the longest days is June (Average daylight: 15.9h).
The month with shortest days is December (Average daylight: 8.5h).

  • Average sunshine in December: 2h

The month with most sunshine is July (Average sunshine: 7h).
The month with least sunshine is December (Average sunshine: 2h).

Average UV index in December - St. John
  • Average UV index in December: 1

Months with the highest UV index are June and July (UV index 7).
Months with the lowest UV index are January, November and December (UV index 1).