The national average precipitation for 2012 clocks in at 790 millimetres, a rain record only beaten by 1998 and 2000 since the Swedish Meteorological and Hydrological Institute (SMHI) began keeping records in 1860.
The wet summer takes most of the credit. The towns of Linköping, Västerås and Piteå all broke their local rain records.
"What happened was that a high pressure weather system over southern Europe made low pressure weather travel up towards us," meteorologist Lisa Frost told the TT news agency.
But while many Swedes were unhappy at seeing their summer holidays rain away, there was one discernible advantage. The reservoirs were filled up.
Sweden generates much of its power from hydroelectric dams.
Only once before have Sweden's dams produced more energy than they did in the past year, Swedenergy (Svensk Energi), the industry's umbrella organisation, said in a statement.
"We'll be able to call this a record year when we sum up the electricity year," said Folke Sjöbohm, power systems head at Swednergy.
He told TT that Sweden's electricity production should clock in at 160 terrawatt hours for 2012.
"Most of it from the hydroelectric dams."
However, Sjöbohm also pointed to figures that electricity generation from wind turbines increased this year, as it has done most years, in addition to Sweden's nuclear reactor fleet experiencing less disruption than in 2011.
"We reached 60 terawatt hours this year and it's been many years since Swedish nuclear energy performed that well," Sjöbohm said.
Swedish power company Vattenfall said that average electricity prices, both for customers on one-year and three-year contracts, were the lowest since 2005.