The freak weather swept over parts of Carinthia and the provincial capital Klagenfurt. Hailstones several centimetres in diameter fell from the sky.
User-contributed images from Der Standard showing hail in Klagenfurt.
Fire brigades were kept busy pumping out basements and removing fallen trees.
Agriculture, too, was severely affected with damage to corn crops.
Because of the storm, the southern railway line was temporarily closed between Klagenfurt and Krumpendorf, due to fallen trees.
"In Krumpendorf the hail was so severe that even the pantograph of a train was damaged," said Austrian Rail (ÖBB) spokesman Christoph Posch. The pantograph is the mechanism on top of an electric train which keeps it in contact with overhead power lines.
In the centre of Klagenfurt traffic came to a halt during the hail storm. The roads were solid white within minutes, with hail later forming a sheet of ice. Leaves clogged drains, causing small lakes and streams.
The hailstones smashed windows and damaged numerous cars. The Klagenfurt city garden department warned people to stay away from trees, until employees could check for the risk of falling branches.
In addition to the state capital, some communities to the north of Klagenfurt were particularly affected.
"This was a very strong thunderstorm, in just ten minutes there were 24mm (one inch) of precipitation," said Stefan Christian from the Central Institute for Meteorology and Geodynamics (ZAMG).
Photo: APA/GERT EGGENBERGER