Swimming days are here

Lake water temperatures across Finland are now a few degrees higher than usual for this time of year. Balmy weather forecast over the next few days will heat up the waters even more – meaning the time is right to break out summer swim gear.

Warm summery days mean it's time to break out the swim gear and hit the beaches. Image: Tommi Parkkinen/Yle

The Finnish Environment Institute reports that waters are warmest on the west coast, where temperature readings have already reached 18 degrees. On the other extreme, the waters of Lake Kilpisjärvi in Lapland are still frozen.

“Temperatures are generally a few degrees higher and in some cases up to five degrees warmer than the average. Typical records for this time of year would be about 10 degrees Celsius,” explained hydrologist Johanna Korhonen of the Finnish Environment Centre.

Current lake water temperatures in southeast Finland range from 12 to 16 degrees Celsius.

“If calm and warm weather is in the forecast, then it could get as warm as 18 degrees in the southeast too by the time school ends,” Korhonen predicted.

Schools across Finland will begin the long summer break following traditional end-of-term ceremonies on Saturday, June 1.

In early summer the warm surface layer on large bodies of water is still very thin, so weather conditions have an immediate impact on water temperature. Strong winds or even a change in wind direction can stir up and lift cold ground water to the surface, causing water temperatures to fall by several degrees in just one day.

“I can promise that water temperatures will be higher than average over the next few days. But if the weather becomes cool and wet, then the water will also cool accordingly,” Korhonen concluded.