In Portugal, Prime Minister Antonio Costa announced a state of public calamity, as 3,700 firefighters battled major fires stretching across the centre and north of the country.
Patricia Gaspar, a civil protection service spokeswoman, told reporters firefighters were still battling 145 fires and 32 of the blazes were considered as serious. At least 51 people have been injured in the fires, she said.
The deaths, confirmed by Portugal's national civil protection agency, came four months after 64 people were killed and more than 250 injured on June 17, in the deadliest fire in the country's history.
The recent fires have been caused by "higher than average temperatures for the season and the cumulative effect of drought, which has been felt since the start of the year", she said.
In Spain, authorities were blaming arson for some 17 fires which have caused three deaths.
"They are absolutely intentional fires, premeditated, caused by people who know what they are doing," the head of the regional government, Alberto Nunez Feijoo, said.
Fifteen separate wildfires which posed a risk to built up areas were raging across the region of Galicia, he said.
The flames were being fanned by wind gusts of up to 90 kilometres (55 miles) per hour as Hurricane Ophelia moved north off the coast of Spain towards Ireland, he told private broadcaster La Sexta.
"The situation is critical," he said.
Unprecedented situation
Feijoo said "thousands" of firefighters, soldiers and locals were battling the blazes.
"We have not had a situation like this in the past decade. We have never deployed so many means at this time of the year," he said.
Prime Minister Mariano Rajoy, who is from Galicia, expressed his condolences to the victims in a Twitter message.
Five wildfires were raging near Vigo, Galicia's biggest city, forcing the evacuation of a shopping mall and a PSA Peugeot Citroen factory on the outskirts of the city.
The flames had reached O Castro, a large hilltop park in the heart of Vigo with sweeping views of the city's estuary, Spanish public television station TVE reported.
Images broadcast on Spanish TV showed local residents, their mouths and noses covered with handkerchiefs, battling the flames with buckets and pans of water.
The city of around 300,000 residents has opened up two sports centres and booked rooms in three hotels for people who were forced to evacuate their homes.
At least 10 schools cancelled classes on Monday in Vigo because of the flames, local officials said.
Spanish state-owned rail operator Renfe said it had cancelled a train linking Vigo to Barcelona because of the wildfires.
Several roads in Galicia were closed because of the flames, local officials said.
The national weather office is forecasting rain and cooler temperatures in Galicia beginning early on Monday which officials hope will help put out the flames.
Meteorologists say Ophelia is the most powerful hurricane recorded so far east in the Atlantic and the first since 1939 to travel so far north.
