Worst-hit was southern Scandinavia. In Sweden, TT news agency said seven people died, including three motorists whose cars were hit by falling trees, as winds of up to 67 miles per hour (mph) hit the south of the country.
The winds left 400,000 Swedes without power and forced the closure of two nuclear power stations. Sturup airport, near Malmo, was briefly closed and ferry traffic stopped, TT said.
Across the Baltic Sea, Latvia's state power company, Latvenergo, said 60 percent of the country's population of 2.4 million was without electricity on Sunday.
"The prime minister has announced that this is an electricity crisis," Arno Pjaktins, spokesman for Prime Minister Aigars Kalvitis, told Reuters.
The military had evacuated people from districts in the capital, Riga, because of flooding, he said.
Danish news agency Ritzau said more than 15,000 households were without power, and the Meteorological Institute issued a severe storm warning for the country as high winds caused widespread disruption to trains and ferry transport.
Danish police said on Saturday two men were killed when they were struck by a roof torn off a cottage on the Island of Funen, while two others were killed by falling trees.
A blackout hit 20,000 households in southern Norway on Saturday night, but power had been restored to most homes by Sunday morning, Norwegian rescue services said.
Power was out at one quarter of Estonia's electricity companies, and mobile and fixed line telephones were also hit, the Baltic News Service said. The Tallinn weather station reported waves of up to 12 metres high in the Gulf of Finland.
In Britain, police searched for two men swept away by overflowing rivers in the north of England, after heavy rain and 90 mph gales ripped through many parts of the country.
Police were also investigating three deaths that may have been caused by the extreme weather.
The Environment Agency issued 25 flood warnings on Sunday and the Met Office warned of more gales and heavy rain to come.
The northwestern English county of Cumbria was hardest hit, with emergency services rescuing hundreds of people from flooded homes after a river burst its banks. The town of Carlisle was swamped with its worst floods for 40 years and electricity was cut to 76,000 homes.
One hundred passengers and crew disembarked on Sunday from a ferry at Cairnryan, off western Scotland, after spending the night on the vessel, which had run aground in gale-force winds.
Hurricane-force winds battered the northern German state of Schleswig-Holstein, ripping up trees, tearing off roofs and blowing cars off roads. Police divers searched Brahmsee lake on Sunday for two canoeists who disappeared during the storm.
(Additional reporting by Kim McLaughlin in Copenhagen, Jackie Dent in London)