Summers in Finland tend to be relatively chilly compared to elsewhere in the world. Since more than a hundred years back, the median June temperature in Helsinki has, more often then not, been less than 15 degrees Celsius. And yet, this summer, we are experiencing colder weather than usual.
From an average June temperature of 14.5 degrees Celsius since 1900, June this year passed with a mean temperature of 13.7 degrees in Helsinki. At first glance, the difference of 0.7 degrees seems almost irrelevant, yet even minor fluctuations in average temperatures are noticeable during a season when a great amount of activities take place outdoors.
As for July, the lowest average temperature in Helsinki at 13.7°C was observed in 1928 and the highest at 21.7°C in 2010. This year, July, not much unlike June, seems to fall in the colder end of the spectrum with an average temperature of 15.3°C so far.
That being said, this summer is not wholly atypical when compared to previous summers. Since 1959, eight summers in Helsinki have seen a colder average temperature from the beginning of June up until mid-July than this one. This summer has thus been just cold enough for us to notice a deviation, yet not quite cold enough to be extraordinary.
The chilly temperatures of this year are also unlikely to be part of a larger trend towards colder summers. On the contrary, we are seeing an overall trend towards warmer average temperatures in Finland. However, according to Niina Niinimäki from the Finnish Meteorological Institute, this trend is not as clear in the summer as the largest impact has been observed during winter months.
On a more positive note, we still have almost six weeks of the summer season ahead of us, and Niinimäki suggests that August could be the warmest month of this year. Indeed, as recently as in the summer of 2015, June and July saw colder temperatures than usual, whereas August was warmer than average with a mean temperature of 17.5°C.