Just a year after the Mayans wrongly predicted the world would end, Nordic mythology has foretold the End of Days with a Viking Apocalypse.

The countdown to Ragnarok has begun, with just 99 days until the world ends on 22 February next year, Norse experts have said.

A horn announced the start of the countdown from a rooftop in York. The horn belonged to the Norse god Heimdallr, who was believed to have blown it to warn people of their impending doom.

Norse mythology says that the god Odin will be killed by the wolf Fenrir and all of the other "creator" gods will fall. The world will then be born again and will be repopulated by two humans.

During the world's end, the sun's beams will become black and the weather will become treacherous, mythology states. "Brothers will fight and kill each other, sisters' children will defile kinship. It is harsh in the world, whoredom rife - an axe age, a sword age - shields are riven - a wind age, a wolf age - before the world goes headlong. No man will have mercy on another," a prophetic poem says.

Experts from the Jorvik Viking Centre say the end of the world will coincide with the grand finale of the 30th Jorvik Viking Festival in York.

Danielle Daglan director of the festival, said: "Ragnarok is the ultimate landmark in Viking mythology, when the gods fall and die, so this really is an event that should not be underestimated.

"In the last couple of years, we've had predictions of the Mayan apocalypse, which passed without incident, and numerous other dates where the end of the world has been pencilled in by seers, fortune tellers and visionaries, but the sound of the horn is possibly the best indicator yet that the Viking version of the end of the world really will happen on 22 February next year."

The festival will run between 15 and 23 February in locations around the city of York and visitors will be offered to eat and drink like Vikings.

"During the week of the Jorvik Viking Festival, we will be doing everything we can to equip the people of York, and visitors from afar, with the tools to survive the apocalypse, from hunting for the mightiest and strongest warriors to training children in combat skills," Daglan said.

"Following a study published in 2010 that bearded men are more trustworthy than those without, we're also looking for fantastic displays of facial hair, so that we can identify those with the potential to take us into the brave new world that is foretold to follow Ragnarok."

Sarah Maltby, director of attractions for York Archaeological Trust, said: "Visitors can expect to see Vikings wandering around just about every street in the city, including a parade from York Minster to Coppergate, learn about Viking combat, continue the tradition of telling ancient sagas, and then join us for a spectacular night-time Festival finale at the Eye of York on Saturday 22 February."