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 (32.9°F) at their highest, winter coats become a necessity. A significant increase in snowfall amplifying to 120mm (4.72") 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

The transition into December in Helsinki subtly indicates a reduction in the average high-temperature, down to a still wintry 0.5°C (32.9°F) from November's icy 3.7°C (38.7°F). A minor drop in temperature is observed from daytime highs during the nights of December, averaging a freezing cold -4.5°C (23.9°F).

Rainfall

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

Snowfall

Months with snowfall are January through March, November and December. During December, Helsinki regularly aggregates up to 120mm (4.72") of snow. Throughout the year, 740mm (29.13") of snow is accumulated.

Sea temperature

In Helsinki, in December, the average water temperature is 3°C (37.4°F).
Note: In swimming, this condition is considered life-threatening and perilous. The painful sensation of cold water leads to immediate hyperventilation. Utilizing a specialized swimsuit is critical to reduce thermal injury.

Daylight

The month with the shortest days is December, with an average of 6h and 0min of daylight.
On the first day of December, sunrise is at 08:57 and sunset at 15:21. On the last day of the month, sunrise is at 09:24 and sunset at 15:22 EET.

Sunshine

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

UV index

The months with the lowest UV index in Helsinki, Finland, are January, February, November and December, with an average maximum UV index of 0. A UV Index reading of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for average individuals.
Note: The maximum UV index of 0 during December leads to these instructions:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.