Since then, strong winds reaching about 80km/h have hampered efforts to put out the blaze and led to new outbreaks.
July is historically the hottest month in the region, accompanied by strong winds, Greek fire service spokesman Vasilios Vathrakoyannis said in a statement.
He added that July was also considered the most difficult of the three-month fire season.
Fires across the Aegean Sea in western Turkey are burning through areas of warning-level drought conditions, according to the European Drought Observatory.
Much of the eastern and northern halves of Europe are dealing with drought, in addition to the recent record heat that has scorched much of the continent.
Erratic and gusty winds in recent days on the edge of high pressure in the region are fanning the flames.
Smoke from the largest fire in western Turkey is blowing southward towards and over Crete, where blazes are also raging.
The fires are occurring amid temperatures about 5 to 10 degrees above average, with some locations seeing even hotter conditions.
In Turkey, afternoon highs are near 38C, while it is more like 30-32C on Crete. Continued heat is expected, with no rain in the forecast.
During the past week, Spain, Portugal and the Alps witnessed all-time heat records for the time of year, with major heat also working into France, Germany and surrounding regions.
Peak fire season in the region tends to overlap with the hottest part of summer and last into early autumn.
Hot, dry conditions have exacerbated destructive fire seasons around the Mediterranean in recent years.
The World Meteorological Organisation, an agency of the United Nations, cautioned that extreme shifts in temperatures around the globe are a rising threat, linked to climate change.
“As a result of human-induced climate change, extreme heat is becoming more frequent and intense,” the agency said in a statement today.
“By 2050, about half of the European population may be exposed to high or very high risk of heat stress during summer.”
Fires also have broken out across northern Scotland, with strong winds pushing the flames and hindering firefighting efforts, similar to the situation in Greece.
In Turkey, four villages were evacuated on account of raging forest fires.
Two farmers were killed while attempting to flee a large blaze in Catalonia, in northeastern Spain, according to local media reports.
The heatwave has set records for June in Spain, Portugal and England.