For ancient Scandinavians all the noise and fire had a very practical purpose - after the long winter the cows and sheep were let out to graze, and making a real ruckus would keep wolves and other dangerous beasts away.
But nowadays the celebrations are more about making us feel better, about welcoming the sun back again and also, hopefully, enjoying some sunny weather.
The modern celebration is named after the christian saint, Walburga, who spread her religion in Germany in the eighth century and has her saint's day on the first of May. So the last of April, is Walburga's night, or walpurgis night.
If you happen to see troops of young people roaming around together on Walpurgis night, that is nothing new either. In southern Sweden the young people of the village would make a procession to 'bring in may' and travel from farm to farm singing springtime rhymes, leaving a green branch on the roof and maybe being paid in food, like eggs.
The universities of Sweden have carried on the tradition of Walpurgis for the young, with Uppsala and Lund claiming to hold the most exciting celebrations, involving eating pickled herring, and the inevitable hard drinking. The state monopoly liquor shops have, in fact, closed their outlets in the centres of those two towns.
High consumption of alcohol has become one of the most talked about problems of Walpurgis, with many Swedish teenagers feeling pressured to open that first can of cider. A report from insurance company If claims that well over a third of Swedish youngsters, those aged between 15 and 18, are planning to get drunk on Walpurgis.
But year the weather will be causing a serious disruption in the Walpurgis celebrations for many - as it has been too warm and dry. So people in north-west Skåne will have to make do, without bonfires or barbecues at all.