The weather in Finland is quite diverse. Being located in the Eurasian continent's coastal zone, Finland is both in a maritime and a continental climate.
Finland's weather is variable and can change very quickly, which is common for weather in Scandinavia. When there are winds from the west, the weather is generally warm and clear in most parts of Finland. Finland is located in the zone where tropical and polar air masses meet, so the Finnish weather tends to change quickly, especially in the winter months. And Finland's weather is not as cold as many think: The Finnish average mean temperatures are higher than that of other regions in the same latitudes, such as south Greenland.
The temperature is raised mainly by warm airflows from the Atlantic, and also by the Baltic Sea.
The summer offers great weather in Finland. In the Finnish South and central Finland, summer weather is mild and warm, just like in other parts of southern Scandinavia, whereas Finland's winters are long and cold. In northern parts of Finland, you can find snow on the ground for upwards of 90 days each year. The mildest weather in winter is found in southwestern Finland amongst the countless islands in the Baltic Sea.
Finland's weather makes a big difference in which month you will want to travel to this Scandinavian country. Finnish weather is the warmest in July and the coldest in February. February is also the driest month in Finland, while August weather is the wettest time of year.
Helsinki is much warmer than many people think, thanks to the currents of the Baltic Sea and the North Atlantic Ocean. Average temperatures during January and February are around 23 degrees Fahrenheit (minus 5 degrees Celsius). Located in the southern part of the country, Helsinki's snowy season is much shorter than other parts of the country. The city also experiences a heat island effect, which results in slightly higher temperatures. Like much of the country, Helsinki experiences long summer days and very low sun during the winter.
Tampere is an inland city in southern Finland. Its climate varies between a humid continental climate and a subarctic climate, with mild summers and winters that are below freezing from November through March. The snow season typically runs from late November through early April. The daily mean temperature is 62 degrees Fahrenheit (17 degrees Celsius) in July and just 21 degrees Fahrenheit (minus 6 degrees Celsius) in January.
Oulu is one of the northernmost large cities in the world. The subarctic climate lends itself to cold, snowy winters and short, warm summers, with an average annual temperature of just 37 degrees Fahrenheit (3 degrees Celsius). The city receives approximately 19 inches of rain each year, typically during July and August. Summers are long, but winters are extremely dark with an average of eight hours of sunshine total during the month of December.
Finland's northernmost region has a subarctic climate with frigid winters and mild summers. December through February is the peak travel season here, as the region is popular with travelers looking to see the Northern Lights. Temperatures average around 16 degrees Fahrenheit (minus 9 degrees Celsius) in December, but can occasionally drop as low as minus 22 degrees Fahrenheit (minus 30 degrees Celsius) with the windchill. The snowy season lasts from October through mid-May. Summertime is warmer, with temperatures between 50 and 60 degrees Fahrenheit (10 to 15 degrees Celsius).