Finland has a predominantly subarctic climate. The majority of the country has a subarctic climate (Köppen climate classification Dfc), with cool summers. The southern coast experiences a humid continental climate (Köppen Dfb), with mild summers. The extreme northwest tip has few regions that fall under the tundra influence (Köppen ET). Finland is a Nordic country in Northern Europe. Finland shares land borders with Russia in the east, Norway in the north, and Sweden in the west. The Gulf of Bothnia lies to the west, the Gulf of Finland to the south, and the Baltic Sea in the southwest. The country's location in the extreme northern latitudes and proximity to major water bodies mainly influence the climate.
Finland lies between the high latitudes of 60°N and 70°N, entirely in the taiga belt. The Arctic Circle passes through the Finnish region of Lapland. The landscape is mostly flat with few hills and mountains. Halti, between the border of Finland and Norway in the extreme north, with an altitude of 1324 meters, is the highest point in Finland. The Finnish Lakeland area has thousands of lakes, while numerous islands dot the Archipelago Sea region in the southwest. Saimaa is the largest lake in Finland, with an area of 1700 square miles. Ridges of sand and gravel run from the northwest to the southeast. Coniferous taiga forests of pine, birch, and spruce cover the landscape along with fens. Wetlands occupy poorly drained areas. The drainage divides of Suomenselka and Maanselka rise high in the west and are colder than areas at similar latitudes.
Winter is the longest season in Finland and lasts from October to mid-May in the extreme north. Polar nights last for 51 days north of the Arctic Circle when the sun does not rise above the horizon. Lakes freeze regularly, and even the seas occasionally solidify at the peak of the winter. Cold air masses from Russia push the temperatures below -20°C (-4°F). The northern and eastern regions are the coldest, and temperatures plummet to -50°C (-58°F) in northern Lapland. The Gulf Stream and the North Atlantic Drift currents prevent the winters from excessive cold. Westerly winds keep the summers cloudy. The continental high-pressure system over Eurasia brings cold winters and high summer temperatures. The Barents Sea is open for navigation even in the winter. Summers are warm and short everywhere except on the southern coast. The sun does not set for 73 days in the summer in the extreme north. Temperatures are usually in the 20°C (68°F) to 30°C (86°F) in much of the country. Nights in Lapland remain cold below 10°C (50°F). Vegetation grows rapidly in the short summer season. The snow melts by the end of April in the cold spring season, and the landscape is prone to floods. September is cold and wet in the autumn.
Finland receives moderate annual rainfall of 508mm (20") to 711.2mm (28"). The northern region registers 482.6mm (19") to 584.2mm (23"), while the south records 584.2mm (23") to 711.2mm (28"). The rainfall occurs throughout the year, with a peak during August in the summer. Half of the annual precipitation in the north falls as snow. Lapland receives first snowfall by September end and the southwestern corner the latest by Christmas. Permanent snow cover of 609.6mm (24") to 914.4mm (36") in the north and 203.2mm (8") to 304.8mm (12") in the south occurs in March. The annual sunshine in Finland is weak and ranges between 1550 hours in northern Lapland to 1800 hours in the southwestern corner. The average seawater temperatures are cold between 0°C (32°F) to 13.9°C (57°F) in the Gulf of Bothnia and 1.1°C (34°F) to 17.2°C (63°F) in the southwest. October to January is the windiest period. Finnish seas register an average of 19 stormy days in the year.
The highest recorded temperature in Finland is 37.2°C (99°F), set on June 29, 2010, in Liperi. The lowest temperature on record is -51.5°C (-60.7°F), set on January 28, 1999, in Kittila, Lapland.
The best time to visit Finland
The best time to visit Finland is from June to mid-August in the summer. Warm temperatures, usually in the range of 17.8°C (64°F) to 22.2°C (72°F), are comfortable for outdoor activities. A few days register in the hot zone of 27.8°C (82°F) to 32.2°C (90°F). Lapland occasionally has cold nights. June is cooler and drier than July, and temperatures begin to decline in the second half of August. Summer has long days and experiences the popular white nights in the south and midnight sun in the north. The least cloudy days occur in the warm season, although the sunshine is moderate.
The worst time to visit Finland
The worst time to visit Finland is generally from November to March, including the icy winter. The days are short, and the sunlight is poor. Christmas is mostly white, and the northern regions do not see the sun for days together. Tourists experience the Aurora Borealis or the northern lights during the peak of the cold season in the north. The south is frigid from December to February. Snow lovers like March, which sees an improvement in daylight amid plenty of snow on the ground. Snowfall is abundant in all regions and highest in the north.
Finland faces weather hazards, mainly in the form of snowstorms, floods, and avalanches. Floods mostly occur during spring after the melting of the snow. Ice dams contribute to winter floods in many regions. Floods cost 10 million euros in damages in 2013. Flooding is the primary reason for residential evacuation and property destruction. Snowstorms in the winter often make roads impassable. Visibility is poor during blizzards, and there are several instances of damage to power lines due to fallen trees. Storms stall everyday life with delays in air traffic, trains, trams, and make road travel dangerous. Treetops and roofs buckle under heavy snow load.
Weather in January
January is the coldest month of the year in Finland, with frigid days and nights. The conditions are cold and dark as polar nights are prevalent in the extreme north, with no sunshine for days together. The Northern Lights are visible during extremely cold days. The average temperatures in Ivalo and Rovaniemi in northern Lapland are in the icy zone of -17.8°C (-0°F) to -7.8°C (18°F). Temperatures fall to extreme lows up to -50°C (-58°F) when cold air masses from Russia invade the country. Helsinki, the capital, in the south, is cold, with average temperatures in the -7.8°C (18°F) to -1.1°C (30°F) zone. Maritime traffic frequently needs icebreakers in the freezing seawaters where average temperatures are below 2.2°C (36°F). The average daily wind speeds are in the high range of 16.1km/h (10mph) to 17.7km/h (11mph) on the southern coasts, but below 8km/h (5mph) in the interior. Precipitation is below 38.1mm (1.5") in most regions, but snowfall is ample, especially in the north. The record high for January in Finland is 10.9°C (51.6°F) in Mariehamn in the southwestern archipelago.
Weather in February
February is cold in Finland, with a slight increase in temperatures and sunshine. The average temperatures in the north are between -17.2°C (1°F) and -7.8°C (18°F), while the south registers in the -8.3°C (17.1°F) to -0.6°C (30.9°F) range. Joensuu, in the east, registers average temperatures in the cold zone of -8.3°C (17.1°F) to -0.6°C (30.9°F) in February. The polar nights end with the sun on the horizon for a daily 2 hours as the daylight registers up to 10 hours in most regions. The skies are overcast up to 80% of the time, but the relative humidity is less than 60%. Snow depth reaches between 304.8mm (12") to 609.6mm (24") in the north. Precipitation is to the tune of 30.5mm (1.2") in many areas, as February is the driest month in Finland. The average seawater temperatures are at 1.1°C (34°F) in Helsinki, the lowest of the year. Expect the conditions to improve gradually by the end of the month. Keep an eye on snowstorms in Finland in February.
Weather in March
March is an extension of the cold winter in Finland, with snow cover in most regions. The snow depth is often the highest in March. Helsinki average temperatures are in the range of -3.9°C (25°F) to 2.2°C (36°F), and most nights are below freezing. The daily sunshine lasts for 4 hours during the 11 hours of daylight. Cloudy skies prevail up to 70% of the time. Rovaniemi is below freezing in March, with average temperatures in the range of -12.8°C (9°F) to -2.2°C (28°F). Much of Finland receives less than 38.1mm (1.5") of precipitation in March. Moderate snowfall occurs in most regions, and snow depth is at the highest of the year. Oulu, in the northern Gulf of Bothnia, records average temperatures between -8.9°C (16°F) and -1.1°C (30°F). The average seawater temperatures in Oulu are at a freezing -1.1°C (30°F), the lowest of the year. March is the best month for a visit to Finland in the winter, with the mildest temperatures during the cold season.
Weather in April
April brings spring season in southern Finland, Aland, and the southwestern archipelago. The spring lasts for 45 days in the north to 65 days in southern coasts and maritime areas. The average daily temperatures register between 0°C (32°F) and 8.9°C (48°F), as the daily sunshine increases to 7 hours. In Rovaniemi and Ivalo, the average temperatures are between -6.1°C (21°F) and 3.9°C (39°F), with cold days and freezing nights. Helsinki is cold in the range of 1.1°C (34°F) to 7.8°C (46°F), but the cloud cover decreases to 54% over the month. Lakes unfreeze, and the growing season begins in the southwest. The precipitation registers below 38.1mm (1.5") in most regions, and snowfall is light at best. The average seawater temperatures are in the cold range of 0°C (32°F) to 2.2°C (36°F) and unsuitable for swimming. The average daily wind speeds decrease from 13.7km/h (8.5mph) to 12.1km/h (7.5mph) on the southern coasts, as westerlies warm the temperatures. The snow melts in most parts of Finland except the north, by Easter in April.
Weather in May
May extends the spring season to the northernmost parts of Lapland. In Ivalo, polar days begin by the fourth week of May, and the sun is continuously on the horizon for the next 73 days. The days are mild in most regions, but nights are freezing. Rovaniemi has average temperatures between 0°C (32°F) and 13.9°C (57°F), with clear skies for 45% of the time. The daily sunshine lasts for 8 hours in much of Finland. The melting of snow causes significant flood events in the spring season. The average temperatures in the southern coastal towns are in the range of 6.1°C (43°F) to 13.9°C (57°F), and the seawaters are cold between 2.2°C (36°F) to 5°C (41°F). Expect less than 38.1mm (1.5") of precipitation everywhere, with a slight bump in the southwest. Cold weather clothing is still helpful, minus a few layers. The southern regions are mostly free from snowfall and snow cover in May. Tourists arrive by late May as the weather improves in Finland.
Weather in June
June is the beginning of the beautiful summer in Finland, with warm days and cold nights. The average daily temperature remains consistently above 10°C (50°F) during the warm season. The daily sunshine lasts for more than 9 hours in much of the country. Northern Lapland, above the Arctic Circle, has polar nights, while the rest of Finland sees at least 18-hour days. The average temperatures in Helsinki are in the 11.1°C (52°F) to 17.8°C (64°F) range, with relative humidity between 55% and 65%. Cloud cover remains for at least 45% of the time. Joensuu is between 6.7°C (44.1°F) and 17.8°C (64°F), with 9-hour sunshine in the 20-hour days. The average daily wind speeds register in the 11.3km/h (7mph) to 12.9km/h (8mph) in the interior. The precipitation is above 50.8mm (2") in most regions, with 8 to 12 wet days. Dress in layers that are easily removable as per the conditions. Expect cold nights in June in the north. June is a beautiful time to visit Finland.
Weather in July
July is usually the warmest month in Finland, as the temperatures rise significantly in the interior. The mercury column remains below 30°C (86°F) near the coasts and maritime islands but reaches 35°C (95°F) in the interior. Heatwaves occur during the peak of the summer but rarely last for more than 8 days at a time. Helsinki registers between 13.9°C (57°F) and 22.2°C (72°F), and the seawaters in the Gulf of Finland are generally in the range of 14.4°C (57.9°F) to 15.6°C (60.1°F). The precipitation registers between 63.5mm (2.5") to 76.2mm (3") in most regions, with a 30% chance of a wet day in July. Expect thunderstorms in the afternoons. The daily sunshine lasts for at least 9 hours, and the daylight is between 18 hours to 24 hours. The average temperatures in Vaasa are between 10.6°C (51.1°F) and 20°C (68°F), and the most comfortable period during the day is between 12 p.m. and 8 p.m. July offers the best weather of the year in Finland.
Weather in August
August is the wettest month in Finland, with an average precipitation of 76.2mm (3") in much of the country. The skies remain overcast for 50% of the time in most regions, and at least one day out of three is rainy. The average temperatures in Helsinki and Turku are between 12.8°C (55°F) and 20°C (68°F), with 9 hours of daily sunshine, and 78.7mm (3.1") of precipitation. Night temperatures drop sharply by the end of the summer in northern Lapland by mid-August. In Ivalo and Rovaniemi, average temperatures register in the mild 5°C (41°F) to 18.9°C (66°F) zone, and the days shorten to less than 15 hours. The seawater is at the warmest of the year, with average temperatures between 13.9°C (57°F) in Oulu and 17.2°C (63°F) in Helsinki. The average daily wind speeds are in the 8km/h (5mph) to 12.9km/h (8mph) range, with a predominantly westerly direction along the coast. A rain jacket and layered clothing are useful in the rainiest part of the summer season. August is an excellent time for a trip to Finland.
Weather in September
September lies in the short autumn season in Finland, with the daily average temperatures between 4.4°C (39.9°F) and 10°C (50°F). The average temperatures in Rovaniemi are cold between 2.2°C (36°F) to 13.9°C (57°F), while Helsinki is in the mild 5.6°C (42.1°F) to 16.7°C (62.1°F) zone. Nights usually remain below freezing in the northern regions. The weak sunshine lasts for 5 hours in the south during the 12 hours of daylight. The southwestern archipelago is the warmest region, with average temperatures in the 7.2°C (45°F) to 15°C (59°F) in the Aland Islands. The first snowfall occurs in Lapland in September, which ends the growing season. Much of the country receives between 55.9mm (2.2") to 71.1mm (2.8") of precipitation. The average seawater temperatures are cold at 13.9°C (57°F) in the Gulf of Finland and not suitable for swimming. September has cloudy skies for 55% to 68% of the time and relative humidity below 65%. Budget travelers find the weather acceptable and accommodation prices light on the wallet in September in Finland.
Weather in October
October is the beginning of the cold winter in much of Finland. The nights are below freezing in much of the country except for the south. Oulu registers cold temperatures in the range of 1.1°C (34°F) to 6.1°C (43°F) and receives 45.7mm (1.8") of precipitation. Vaasa is slightly mild between 0°C (32°F) and 10°C (50°F), with cloudy skies for 60% to 70% of the time. The daylight fades gradually to last only 8.5 hours, and the sunlight is hardly for 2 hours. Turku, on the southwest coast, is between 1.1°C (34°F) to 11.7°C (53.1°F), with average seawater temperatures in the cold 7.8°C (46°F) to 11.7°C (53.1°F) range. Snowfall occurs in much of the country except the south. The daily average wind speeds remain in the 11.3km/h (7mph) to 12.9km/h (8mph) range on the southern coasts, with a predominantly southern direction. Expect frequent cold fronts from the north and east that further push down the temperatures. The conditions gradually worsen by the second half of October in Finland.
Weather in November
November lies in the icy winter in Finland, with cold and dark conditions. The daily sunshine lasts for hardly 1 hour as the skies remain overcast for 70% to 80% of the time. The daylight decreases to slightly less than 4 hours near the Arctic Circle to 6.5 hours in the southwest by the second half of the month. Helsinki registers average temperatures in the cold -0.6°C (30.9°F) to 3.9°C (39°F) region, with many freezing nights. The average temperatures in Rovaniemi are generally in the frigid zone of -6.1°C (21°F) to -1.7°C (28.9°F), and the region is bereft of sunshine. The daily average wind speeds are between 8km/h (5mph) in the north to 16.1km/h (10mph) in the southern coasts. The average seawater temperatures at 5°C (41°F) in Oulu in the northern Gulf of Bothnia are colder than Helsinki in the south at 7.2°C (45°F). Precipitation is between 38.1mm (1.5") and 50.8mm (2"), and snowfall is prevalent everywhere. November is usually a time to avoid Finland, even in the warmest winter clothing.
Weather in December
December is a peak winter month in Finland, with temperatures below freezing during days and nights. The skies remain cloudy between 71% and 85% of the time. Lakes, rivers, and seas freeze, many a time as far as Helsinki in the south. The north and east are frigid, with temperatures in the average zone of -16.1°C (3°F) to -4.4°C (24.1°F) in Ivalo and Joensuu. Helsinki registers average temperatures between -4.4°C (24.1°F) to 0°C (32°F). December 21 is the shortest day in Helsinki, with 5 hours and 49 minutes of daylight. In Ivalo, polar nights begin from December 2, and the sun does not rise again for more than 43 days. Snowfall is rampant, especially in the north, but the rainfall registers below 38.1mm (1.5"). The average seawater temperatures are at 2.8°C (37°F) in the northern part of the Gulf of Bothnia. Winter clothing, such as thermal underwear, parka, boots, and gloves are a must for outdoors. Christmas is usually white under a blanket of snow in December in Finland.