A rare Mediterranean hurricane, known as a medicane, swept through western Greece on Friday, flooding streets and homes.
The storm, named Ianos, uprooted trees, flooded highways and caused power cuts in the Ionian islands of Kefalonia, Zakynthos and Ithaca.
The body of one man was found under the collapsed roof of his house; another 63-year-old man was found dead in the same area; and, the body of an elderly woman was found nearby Farsala, as reported by brigade officials.
Officials are still searching for a woman reported missing in Karditsa.
Experts report that about 5,000 houses were flooded in the area of Karditsa.
Greece Prime Minister Kyriakos Mitsotakis, who is planning to visit the affected region within a few days, says the government will provide economic assistance to the affected areas.
The fire brigade reportedly received more than 2,450 calls for assistance, mainly to cut down trees, rescue trapped people and pump water from homes and stores.
Authorities say cyclones were appeared in Greece in 1995, becoming more frequent in recent years.
A similar storm hit Greece in 2018 and flash floods in 2017 killed 25 people and left hundreds homeless.