December weather forecast
Helsinki, Finland

With December, Helsinki embraces the full onset of winter and the festive season. As temperatures dive to the lower side, peaking only at 0.5°C at their highest, winter coats become a necessity. A significant increase in snowfall amplifying to 120mm paints the city in a winter wonderland motif. Brief daylight hours reminiscent of January's patterns coupled with scanty sunshine encapsulates the hushed calmness of Finnish winter. Amidst the chilling temperatures, December in Helsinki carries its unique winter charm and festive spirit.

Temperature

Helsinki experiences a moderate temperature shift at the start of December, with average high-temperatures adjusting a bit from 3.7°C in November to a still cold 0.5°C. December nights witness a slight temperature decrease, averaging at a subzero cold -4.5°C.

Rainfall

In Helsinki, during December, the rain falls for 20 days and regularly aggregates up to 58mm of precipitation. In Helsinki, during the entire year, the rain falls for 182 days and collects up to 655mm of precipitation.

Snowfall

Months with snowfall are January through March, November and December. In Helsinki, in December, 120mm of snow is typically accumulated. Throughout the year, 740mm of snow is accumulated.

Sea temperature

In December, the average sea temperature in Helsinki is 3°C.
Note: In swimming situations, the extreme cold and danger can lead to fatality. Without the protection of insulated waterproof gear, hypothermia takes effect quickly.

Daylight

With an average of 6h and 0min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 08:55 and sunset at 15:22. On the last day of December, sunrise is at 09:24 and sunset at 15:21 EET.

Sunshine

With an average of 0.9h of sunshine, December has the least sunshine of the year in Helsinki.

UV index

January, February, November and December, with an average maximum UV index of 0, are months with the lowest UV index in Helsinki. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV rays for average individuals.
Note: In December, the average maximum UV index of 0 translates into the following recommendations:
It is important to always shield children, babies, and individuals with sensitive skin from prolonged exposure to the sun. To avoid the Sun's strongest rays, limit exposure around the mid-day period. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.