Helsinki, where it's located

The climate of Helsinki is Baltic, that is, moderately continental, with cold winters, during which the average temperature is a few degrees below freezing, and mild to pleasantly warm summers.
The city, the capital of Finland, is located on the southern coast, at the 60th parallel. On December 22nd, the sun rises at 9:25 and sets at 14:15. Instead, the white nights occur from 12 May to 2 August.
In winter, the temperature can drop to -30 °C (-22 °F); in January 1987 it even went down to -36 °C (-33 °F). In one year there are 130 days with temperatures below freezing. Generally, snow covers the ground from December 10 to April 10, with a maximum of 20/25 cm (8/10 in) from late February to mid-March. Generally, on the hottest days of the year, the temperature reaches 28/30 °C (82/86 °F), although in 2010, it reached 34 °C (93 °F). On average, only 9 days a year with highs above 25 °C (77 °F) are recorded.
The average temperature of the coldest month (February) is of -4.7 °C (24 °F), that of the warmest month (July) is of 17.9 °C (64 °F). Here are the average temperatures.
Helsinki - Average temperatures
Min (°C)-6-7-41611141394-1-4
Max (°C)-1-2281418222015940
Min (°F)211925344352575548393025
Max (°F)302836465764726859483932

Precipitation amounts to 650 millimeters (25.6 inches) per year: so, it is at an intermediate level. It ranges from 35 mm (1.4 in) in the driest months (February, March, April, May) to 80 mm (3.1 in) in the wettest (August). Here is the average precipitation.
Helsinki - Average precipitation

On average, there are around 1,780 sunshine hours per year. Here are the average sunshine hours per day.
Helsinki - Sunshine

The sea temperature ranges between 1 °C (34 °F) and 17 °C (63 °F): so, it never becomes warm for swimming. During the coldest periods, the sea can freeze, though less often than in the Gulf of Bothnia. Here are the average sea temperatures.
Helsinki - Sea temperature
Temp (°C)2112591517141073
Temp (°F)363434364148596357504537


Best Time

The best time to visit Helsinki is the summer, from June to August, since it is the mildest season. However, you must take into account some rainy days and a bit of cold at night.