Despite the weather fluctuations in the last few weeks, the temperatures of Finland's lakes have surprisingly not taken a nosedive. According to measurements by the Finnish Environment Institute (Syke), inland water temperatures are at around 18 degrees Celsius everywhere but northernmost Lapland.
Highs of some 20 degrees have been recorded in the Pesiöjärvi lake in Suomussalmi near Kainuu. The coldest spot recorded was the Näsijärvi lake in Pirkanmaa at under 15 degrees Celsius.
"Water temperatures follow the temperature of the air closely," says Syke's hydrologist Heidi Sjöblom. "If it's calm and warm, surface temperatures will heat up quickly. If the temperature drops or it rains, the water will likewise cool down very fast."
Heat records were broken in late May this year, but a cool June kept waters chilly. Inland water temperatures have already fallen several degrees since temperatures were at their highest.
Traditionally, the month to feature the warmest inland water temperatures in Finland is August. Maybe the best is yet to come.
