December weather forecast and climate
Helsinki, Finland

A scenic reflection in the water of the illuminated city of Helsinki in Finland, viewed from the water
A scenic reflection in the water of the illuminated city of Helsinki in Finland, viewed from the water
December, the first month of the winter, in Helsinki, is still a cold month, with temperature in the range of an average low of -4.5°C (23.9°F) and an average high of 0.5°C (32.9°F).

Temperature

In December, the average high-temperature slightly decreases, from a cold 3.7°C (38.7°F) in November, to a still wintry 0.5°C (32.9°F). The average low-temperature, in Helsinki, Finland, is -4.5°C (23.9°F).

Rainfall

In Helsinki, during 20 rainfall days, 58mm (2.28") of precipitation is typically accumulated. In Helsinki, during the entire year, the rain falls for 182 days and collects up to 655mm (25.79") of precipitation.

Snowfall

January through March, November and December are months with snowfall in Helsinki. Throughout December, 120mm (4.72") of snow is accumulated. Throughout the year, 740mm (29.13") of snow is accumulated.

Sea temperature

In December, the average sea temperature is 3°C (37.4°F).
Note: For swimming, this is considered life-threatening and very dangerous. The water feels painfully cold, and hyperventilation quickly occurs. A specialized swimsuit is mandatory to reduce thermal damage.

Daylight

With an average of 6h of daylight, December has the shortest days of the year.

Sunshine

The month with the least sunshine in Helsinki is December, with an average of 0.9h of sunshine.

UV index

January, February, November and December, with an average maximum UV index of 0, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health vulnerability from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: In December, the average maximum UV index of 0 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 solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.

What is the temperature in December in Helsinki?

In December, in Helsinki, Finland, the average high-temperature is 0.5°C (32.9°F), and the average low-temperature is -4.5°C (23.9°F).

How much does it rain in Helsinki in December?

In December, the rain falls for 20 days. Throughout December, 58mm (2.28") of precipitation is accumulated.

How much does it snow in Helsinki in December?

During December, Helsinki regularly aggregates up to 120mm (4.72") of snow.

What is the water temperature in December in Helsinki?

In Helsinki, the average seawater temperature in December is 3°C (37.4°F). 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.

What is the month with the shortest days in Helsinki?

December has the shortest days of the year in Helsinki, with an average of 6h of daylight.

How many hours of daylight does Helsinki have in December?

In December, the average length of the day in Helsinki, Finland, is 6h.

What is the month with the least sunshine in Helsinki?

The month with the least sunshine in Helsinki, Finland, is December, with an average of 0.9h of sunshine.

How many hours of sunshine does Helsinki have in December?

In December, the average sunshine is 0.9h.

What are the months with the lowest UV index in Helsinki?

Months with the lowest UV index are January, February, November and December, with an average maximum UV index of 0.

How high is the UV index in December in Helsinki?

In December, the average daily maximum UV index in Helsinki is 0. A UV Index estimate of 2, and below, represents a low health risk from unprotected exposure to the UV radiation.
Average temperature in December - Helsinki, Finland
  • Average high temperature in December: 0.5°C

The warmest month (with the highest average high temperature) is July (21.5°C).
The month with the lowest average high temperature is February (-1.9°C).

  • Average low temperature in December: -4.5°C

The month with the highest average low temperature is July (14.2°C).
The coldest month (with the lowest average low temperature) is February (-7.4°C).

Average rainfall in December - Helsinki, Finland
  • Average rainfall in December: 58mm

The wettest month (with the highest rainfall) is August (80mm).
The driest month (with the least rainfall) is April (32mm).

Average rainfall days in December - Helsinki, Finland
  • Average rainfall days in December: 20 days

The month with the highest number of rainy days is December (20 days).
Months with the least rainy days are April and May (11 days).

Average snowfall in December - Helsinki, Finland
  • Average snowfall in December: 120mm

The month with the highest snowfall is February (230mm).
Months with the least snowfall are April, May, June, July, August, September and October (0mm).

Average sea temperature in December - Helsinki, Finland
  • Average sea temperature in December: 3°C

The best month for swimming (with the highest average sea temperature) is August (16°C).
The coldest months (with the lowest average sea temperature) are February and March (1°C).

Average daylight in December / Average sunshine in December - Helsinki, Finland
  • Average daylight in December: 6h

The month with the longest days is June (Average daylight: 18.8h).
The month with the shortest days is December (Average daylight: 6h).

  • Average sunshine in December: 0.9h

The month with the most sunshine is June (Average sunshine: 9.9h).
The month with the least sunshine is December (Average sunshine: 0.9h).

Average UV index in December - Helsinki, Finland
  • Average UV index in December: 0

Months with the highest UV index are June and July (UV index 5).
Months with the lowest UV index are January, February, November and December (UV index 0).