Weather overview for Helsinki
The capital of Finland, Helsinki lies at a crossroads between Scandinavia and Russia. This far-northern city has long and dark winters, with a brief and mild summer. Due to its coastal location however, the winter is more mild than further north in Finland. A seaside city, most travelers aren't visiting for the beaches, as the sea temperature rarely warms beyond 25 degrees. However, the intricate archipelago unfolding from the city still has plenty of riches to offer. The historic Suomenlinna Fortress is a fascinating island that is one of the most popular destinations in the area, perhaps matched only by the Seurasaari open air museum, also located on an island, which offers guests the chance to see a hands-on version of history.
Travelers visiting Helsinki in the summer will find cool temperatures and slightly rainy weather as they explore the outdoors, while those visiting in the harsh winters will want to explore indoors, visiting famous buildings like the stunning Helsinki Cathedral or the stark Central Railway Station. Though its history as an independent nation began only in 1917, the Finnish have a strong and unique personality, welcoming visitors in and offering delicious cuisine and renowned architecture to all who will brave the northern weather.
Summer Weather in Helsinki
Summers are mild in this far northern destination. July is the hottest month of the year, though the average daily temperature is still only 17°C. Highs in July can be as warm as 21°C, though lows will still drop down to a cool 12°C. The warmer weather takes a little longer to reach the sea, and water temperatures don't reach their highest point until August, when the sea warms to 13°C. While still cold, many locals enjoy the water and jump in for a quick swim.
As the sea warms, humidity increases and the chance of rain increases as well. August is the wettest month of the year, typically receiving 90mm of rain throughout the month, with a chance of rain on approximately 17 days of the month.
June marks the summer solstice and the longest day of the year: Midsummer. This day is celebrated with bonfires and festivities throughout the city, as the sun makes its long journey overhead, with a 19 hour day. The long days last all month long, starting to shorten just a tad in July, when daylight typically lasts around 18 hours. This is the most popular time of the year for tourists to visit Helsinki, as the long days and mild weather allow plenty of time to explore.
Autumn Weather in Helsinki
Tourism begins to drop off again as students head back to school around the world and the weather begins to cool down again in Helsinki. September has a daily average temperature of 10°C, which will rapidly drop to 6°C in October and 0°C in November. The average high temperature in October is just 8°C, while the low stays just above freezing at 3°C.
Rainfall remains fairly high throughout the autumn season, with September and November each receiving an average of 80mm of rain throughout the month, similar to its neighboring capital in Oslo, Sweden. October has the most days of rain, with approximately 20, totalling 70mm of rain on average. Wind speeds pick up to 16 km/hour during autumn as well.
Though the weather turns cold in autumn, the sea holds onto a bit of warmth, with the average sea temperature being 10°C in September. It drops down to 4°C by November. A slight chance of snow begins in November, though Helsinki typically doesn't see much snow covering the ground until later in winter.
The days begin to shorten throughout autumn. With December approaching and bringing the winter solstice and the shortest day of the year, the sun rise begins to come later and the sun set comes earlier. At the beginning of September, tourists will have long, 14 hour days to explore the city. By the end of November though, the daylight will only last 6 hours and 30 minutes. As students return to school across the world, tourists who are able to visit Helsinki in autumn will find a less crowded city, lower priced accommodations, and brisk weather perfect for enjoying the sauna culture of Helsinki.
Winter Weather in Helsinki
Winters in Finland are long and cold, though Helsinki fares slightly better than the rest of the country, thanks to its seaside locale. Average daily temperatures drop from 0°C in November down to -6°C in February, the coldest month of the year. The daily high in February rarely goes above freezing, hovering just below at -1°C. Lows typically dip down to -10°C. Snow tends to blanket the city, though they don't get quite as much as areas like Lapland, where skiing is popular. The city is prepared for the cold and is home to plenty of cozy cafes and fun activities like ice skating.
Rainfall in the winter varies from 40mm-60mm in a month, with anywhere from 11-16 rainy days in a given month. Sea temperatures drop from 4°C in November down to freezing in February. The water doesn't warm up above 0°C until April. However, there are heated pools available at many hotels throughout the area. The days are short in the winter; December sees the shortest day, lasting just 5 hours and 50 minutes, leaving more than 18 hours of darkness. However, by the time February arrives, daylight is lasting nearly 10 hours. Visitors to the area will find beautiful city lights once the sun sets, as the city brilliantly shows off to combat the darkness, particularly around Christmas.
Spring Weather in Helsinki
Spring arrive slowly in Helsinki, with March daily averages remaining below 0°C, at just -2°C. The weather doesn't truly warm up until May, when the average daily temperature reaching a cool 10°C. Lovers of the sun, the Finns typically celebrate May Day with parades, picnics, and concerts all over the capital city. In May, the average high temperatures is a lovely 15°C, while the low is still brisk at 4°C.
The sea is slow to catch up, remaining at 0°C until May, when it warms to just 3°C. Opposite of many areas, spring does not bring showers to the area. Helsinki's driest season is between February and May, with April, the driest month, receiving only 30mm of rain on average. The days begin to lengthen in the spring; March starts off with 10 hours and 30 minutes of sunlight. By the end of May, the capital city will receive more than 18 hours of sunlight, creating short nights. Long days and little rain make spring a beautiful time to visit Helsinki, Finland. Because it is still quite cool in the spring, the city doesn't reach its busy season until summer, making spring an excellent time to find cheaper accommodations and less crowded attractions.
Extreme Weather in Helsinki
The seaside location of Helsinki keeps the city's weather more moderate than the areas further inland, like Lapland. Most of Finland's extreme weather incidents have occurred further north in the country. However, Helsinki has been home to a few of the hottest days in Finnish history, including the hottest February day (11.8°C in 1943) and the hottest March day (17.5°C in 2007). The hottest October day in Finland also occurred in Helsinki in 1985 at 19.4°C. In Helsinki's own recorded history, the hottest day ever recorded was 31.6°C.
The coldest day in Helsinki's recorded history occurred in 1987, when temperatures dropped to -34.3°C. The dead of winter tends to hit the city in January and February, well after the winter solstice, as the sea's warmth slows winter's progress early on.
The summer brings a few thunderstorms in from the warming sea. These thunderstorms can be very strong and bring damaging winds and occasionally hail too. Tourists should keep an eye on thunderstorm conditions when planning outdoor activities.