Athens had a month's rain six times over, and the drains got the bill

Violent storms hit the Athens region on Monday. Floodwater carrying debris ran through the streets of Mandra and the seaside village of Porto Germeno, west of the capital, and some areas recorded as much as 40 millimetres of rain in an hour¹. No injuries were immediately reported¹.

The station network of the National Observatory of Athens counted 104 mm at Ellinikon, on the city’s southern coast, over Sunday and Monday up to 18:00, and 133 mm at Amoni Sofikou in the north-eastern Peloponnese, the country’s highest total up to 17:50². This is the fourth time this October that parts of Greece have been at risk of flooding³; earlier floods hit Crete, Evia, Rhodes and Argostoli on Kefalonia¹.

How unusual is that? A modelled grid point over central Athens puts the rain since 1 October at 128.2 mm, against a 1991–2020 average of 20.1 mm for the same 26 days⁴. Desk arithmetic: more than six times the usual amount. Model grids smooth out cloudbursts, so local gauges read higher; the shape of the month is the point, not the decimal.

Mandra is not a random name. Flash floods there killed 24 people in November 2017¹. What has changed since is mostly invisible: stream beds cleared, culverts widened, warnings sent to phones. Monday’s floods without reported injuries are a small receipt for that work, not proof that it is finished.

The weather is not done. A meteorologist told iefimerida.gr that “another, stronger low-pressure system from central Europe” will bring rain again on Wednesday, locally heavy, across almost the entire country, with bad weather into Thursday before it eases on Friday¹. If you are travelling to Greece this week, check the civil-protection warnings before the ferry timetable.