The climate in Finland
The main factor influencing Finland's climate is the country's
geographical position between the 60th and 70th northern parallels in
the Eurasian continent's coastal zone, which shows characteristics of
both a maritime and a continental climate, depending on the direction of
air flow. The mean temperature in Finland is several degrees (as much as
10°C in winter) higher than that of other areas in these latitudes, e.g.
Siberia and south Greenland. The temperature is raised by the Baltic
Sea, inland waters and, above all, by airflows from the Atlantic, which
are warmed by the Gulf Stream.
When westerly winds prevail, the weather is warm and clear in most of
the country due to the 'föhn' phenomenon caused by the Keel range.
Despite the moderating effect of the ocean, the Asian continental
climate also extends to Finland at times, manifesting itself as severe
cold in winter and extreme heat in summer.
Since Finland is located in the zone of prevailing westerlies where
tropical and polar air masses meet, weather types can change quite
rapidly, particularly in winter. The systems known to affect Finnish
weather are the low-pressure system usually found near Iceland and the
high-pressure systems in Siberia and the Azores. The position and
strength of these systems vary, and any one of them can dominate the
weather for a considerable time.
According to Köppen's climate classification, Finland belongs wholly to
the temperate coniferous-mixed forest zone with cold, wet winters, where
the mean temperature of the warmest month is no lower than 10°C and that
of the coldest month no higher than -3°C, and where the rainfall is, on
average, moderate in all seasons.