Around 10,000 Fortum, 11,000 Elenia, 8,000 Kymenlaakson Sähkö and 3,000 Suur Savon Sähkö customers suffered power cuts.
The affected areas are in Uusimaa, Häme, Pirkanmaa, Finland Proper, Kymenlaakso and South Savo. Fortum said that some of its customers in Porkkala, Kirkkonummi, Nummi-Pusula, Parainen and Salo were cut off, and that around 250 fitters were out working to restore supplies.
In Häme and Pirkanmaa around 10,000 Elenia customers lost electricity, with Hämeenlinna and Urjala affected. Kymenlaakso saw 7,900 households lose connections to the grid, with a further 4,500 in South Savo cut off.