Tens of thousands of people have already fled blazes on the island of Rhodes, with many frightened tourists scrambling to get home on evacuation flights.
About 2,400 visitors and locals were evacuated from the Ionian tourist island of Corfu from Sunday into Monday, a fire service spokesman said, adding that the departures were a precaution.
Fires were also burning on Greece's second largest island of Evia on Monday.
"We are at war and are exclusively geared towards the fire front," Greek Prime Minister Kyriakos Mitsotakis told parliament, warning that the nation faced "another three difficult days ahead" before high temperatures are forecast to ease.
Vassilis Kikilias, Greece's civil protection minister, said crews had battled over 500 fires around the country for 12 straight days.
Greece has been sweltering under a lengthy spell of extreme heat that has exacerbated wildfire risk and left visitors stranded in peak tourist season.
The government's speedy evacuation came after a tragedy in 2018 when over 100 people perished in Greece's deadliest forest fire at Mati, near Athens, which Mitsotakis on Monday said still "haunts us all".
Because of the wildfires, an annual celebration on Monday to mark the 1974 restoration of democracy in Greece was cancelled.
Rhodes, which counted 2.5 million visitor arrivals in 2022, is one of Greece's leading holiday destinations.
Travel giant TUI on Monday said it was suspending holiday packages to Rhodes until Friday.
Greek television broadcast images of long lines of people, some in beachwear, lugging suitcases along the island's roads on Saturday, when the evacuations were ordered.
"We walked for about six hours in the heat," Kelly Squirrel, a transport administrator from the United Kingdom, told AFP at Rhodes airport.
Some 30,000 people fled the flames on Rhodes at the weekend, the country's largest-ever wildfire evacuation.
Police said 16,000 people had been transported on land and 3,000 evacuated by sea. Others had to flee by road or used their own transport after being told to leave the area.
"We are exhausted and traumatised," said Daniel-Cladin Schmidt, a 42-year-old German tourist waiting to be evacuated with his wife and nine-year-old son.
"There were thousands of people, the buses couldn't pass, we had to walk for more than two hours," he told AFP at the airport.
"We couldn't breathe, we just covered our faces and moved forward."
Holiday-makers and some locals spent the night in gyms, schools and hotel conference centres on the island.
In the departures hall of the international airport, AFP saw groups of tourists sleeping on the floor, surrounded by luggage.
"We had to lend a woman some of my wife's clothes because she had nothing to wear," Kevin Sales, an engineer from England, told AFP. "It was terrible."
Several travel companies have halted their inbound tourist flights to Rhodes, and have been helping to ferry foreigners home.
"We ran 10 kilometres with all our luggage to escape the flames", while the temperature was 42 degrees Celsius, said German tourist Lena Schwarz, after arriving at Hanover airport overnight Sunday into Monday.
The 38-year-old told AFP their journey leaving Rhodes was "hell on Earth".
Oxana Neb, 50, also arriving at Hanover, said the evacuation had been "very bad".
"We stayed in the hotel until the end and fire came from all sides," she said.
She joined other guests running to the beach, eventually abandoning her suitcases on the way, she said.
Like every summer, Greece is plagued by forest fires, often deadly, ravaging tens of thousands of hectares of forest and vegetation.
This summer, Greece experienced one of the longest heatwaves in recent years, according to experts, with the thermometer hitting 45 degrees Celsius at the weekend.
Temperatures eased Monday but were expected to to pick up again on Tuesday and Wednesday.
Rhodes on Tuesday remains at the highest level of fire alert, alongside Crete.
