What happens when you scream out of your window at 10pm in Flogsta, Sweden

IN most neighbourhoods, screaming out of your window at 10pm won’t make you any friends. But in one Swedish town, things are different.

This photo provided by Sotheby's shows painting 'The Scream', 1895, by Norwegian painter Edvard Munch. The work, is one of four versions of the composition, will lead Sotheby's Impressionist & Modern Art Evening Sale in New York on 02/05/2012.

IN most neighbourhoods, screaming out of your window at 10pm won’t make you any friends.

But in one Swedish town, things are very different.

Residents of Flogsta, Uppsala, have been echoing each other’s frustrated cries for years.

Every night since the 1970s, someone has leaned out of their window and begun a mass wailing session.

Now, the strange phenomenon has spread to other towns in Sweden, where locals know exactly what to do when they hear the “Flogsta Scream”.

A video of the bizarre custom made by a young man living in Lappis, in the Swedish city of Stockholm, went viral on Reddit today.

Users from American cities commented that doing the same in their hometown would get you screamed at in a very different way — or perhaps even shot.

Flogsta is home to many apartment blocks housing students from Uppsala University, and it is thought the yelling began as a way to relieve stress at exam time. Another theory is that it began as a tribute to a student who took their own life.

Everyone in Flogsta is a noisy neighbour. Picture: Google Maps

Whatever the reason, Flogsta residents confirm that the screaming is daily, but usually only lasts for about five minutes, and is loudest on weekends.

One Swedish student said he didn’t know of the practice when he moved to the town.

“When I approach my building I hear this distant howl, then another, and another,” he wrote. “And then the night was filled with screaming students. The confusion I felt at that time was staggering, and close to terror.”

The screaming now also happens in student area of Lappkarrsberget in Stockholm and in Lund, southern Sweden.

Several other Reddit commenters revealed similar practices, with Michigan State University and Central Michigan University performing “midnight screams” every evening during finals week.