Athens hit with several months of rain in one day: expert
Wednesday's storm lashed the country and left two dead, with disaster crews spending Thursday cleaning up debris.
Kostas Lagouvardos, research director at the National Observatory in Athens, said the "extreme" weather phenomenon had dumped up to 170 millimetres of rain on the capital.
That amounted to "about 40 percent of the rain that falls annually in Athens", he told AFP on the sidelines of a presentation of annual weather data for Greece.
A 56-year-old woman died on Wednesday evening after being carried away by floodwater and trapped under a car in the Athens hillside suburb of Ano Glyfada.
Hours earlier, a 53-year-old coastguard was hit by a wave and fatally hurt whilst trying to help locals secure their boats in the Peloponnese port town of Astros.
The storm front moving eastwards across Greece saw winds exceed 100 kilometres (62 miles) an hour, prompting authorities in Athens and in the west and the south to shut schools.
The fire department said it had responded to over 900 flood-related emergency calls across the capital.
Prime Minister Kyriakos Mitsotakis cancelled a planned trip to the World Economic Forum in Davos, Switzerland.
Deadly flooding in Greece during intense rainfall in recent years has forced the authorities to improve floodworks to limit damage.
In September 2023, the agricultural region of Thessaly in central Greece was devastated by a storm and catastrophic flooding that left 17 dead and drowned hundreds of thousands of farm animals.
In November 2017, heavy rain in Mandra, a semi-rural region near Athens, left 25 dead and dozens injured.
Experts have repeatedly called for infrastructure upgrades, especially in the greater Athens area, which is surrounded by mountains and crisscrossed by hundreds of waterways, most of them covered to accommodate rampant urbanisation in recent decades.