linguistic:translation
Climate

Helsinki has a humid continental climate (Köppen: Dfb). Due to the moderating influence of the Baltic Sea and the North Atlantic Current (see also Extratropical cyclone), winter temperatures are higher than the northern location would suggest, with an average of −4 °C (25 °F) in January and February.

Winters in Helsinki are significantly warmer than in the north of Finland, and the snow season in the capital is much shorter due to its location in the extreme south of Finland and the urban heat island effect. Temperatures below −20 °C (−4 °F) occur only a few times a year. However, due to the latitude, the days around the winter solstice are 5 hours and 48 minutes long, with the sun very low (at noon the sun is just over 6 degrees in the sky), and the cloudy weather at this time of year exacerbates the darkness. Conversely, Helsinki enjoys long days in summer, with 18 hours and 57 minutes of daylight around the summer solstice.

The average maximum temperature from June to August is around 19 to 22 °C (66 to 72 °F). Due to the sea effect, especially on hot summer days, daytime temperatures are slightly cooler and nighttime temperatures higher than further inland. The highest temperature recorded in the city was 33.2 °C (91.8 °F) on 28 July 2019 at the Kaisaniemi weather station, breaking the previous record of 33.1 °C (91.6 °F) set in July 1945 at the Ilmala weather station. The lowest temperature recorded in the city was −34.3 °C (−29.7 °F) on 10 January 1987, although an unofficial low of −35 °C (−31 °F) was recorded in December 1876. Helsinki Airport (in Vantaa, 17 km north of Helsinki city centre) recorded a maximum temperature of 33.7 °C (92.7 °F) on 29 July 2010 and a minimum of −35.9 °C (−33 °F) on 9 January 1987. Precipitation comes from frontal passages and thunderstorms. Thunderstorms are most common in summer.