Helsinki usually gets 70-80 millimetres of rain during August. Friday morning alone brought 56 mm of water to Kaisaniemi Park, where the Finnish Meteorological Institute (FMI) has a weather station.

The highest flood levels in Finland's measurement history are predicted to hit Rovaniemi. The cities of Tornio and Kittilä also expect extensive water damage.

In Northern Ostrobothnia the floods are rising faster, and local emergency services have elicited the help of the military as a precaution, in case some of the ice dams in the riverland should need to be detonated.

Packed ice crystals have pushed up water levels on the Kokemäki River, soaking some buildings in Huittinen and Pori.

Mild, wet weather has raised water levels in rivers and lakes around the country.