Flash floods were triggered by rainfall from the arrival of Storm Daniel on Monday September 4 which also affected Turkey and Bulgaria. The following day, in the village of Zagora, a record-breaking 754mm of rain fell in just 18 hours, leaving parts of the region of Thessaly in crisis and unable to respond.
To put this in perspective, London gets about 585mm of rain over the course of a year while Thessaly gets 495mm, meaning that on Tuesday, about 1.5 years’ worth of rain fell in 18 hours. Imagine the most torrential rain you have ever experienced, perhaps a cloudburst lasting 20 minutes or so. Now imagine it raining that hard but without pause for an entire day.