NOA counts more than 3,000 lightning strikes in one day.
More than 3,000 lightening strikes were recorded Greece on August 15, with the biggest frequency detected in central regions of the country during rainstorms, according to the National Observatory of Athens.
The electrostatic activity was detected by the ZEUS long-range lightning detection system operated by the observatory.
The highest levels of rain were recorded in Serres with 25 mm, in the area of Vlasti near Kozani with 16 mm and in Lamia with 15 mm, while many other areas received more than ten millimeters of rain in less than an hour.
Weather will remain unstable on Friday, with storms affecting northern parts of the country from the afternoon.