On April 17, 2023, the famous Böögg snowman took 57 minutes to explode, a record-long time for what is perhaps the strangest weather forecast in the world. However, before we all assume that the events of Sechseläuten hail the start of a terrible summer, we ask the question: how accurate has the Böögg actually been in predicting the weather?

Sechseläuten: the world's strangest weather forecast

As events in Switzerland go, Sechseläuten has to be one of the strangest. As part of the famous tradition, the guilds or Zunfts of Zurich symbolically set fire to a large pyre of wood with a model of a snowman on the top, called the Böögg. The head of the snowman is filled with explosives, meaning once the fire reaches the top of the statue, a large explosion can be heard as the head combusts into a pile of ash and smoke.

It is said that the amount of time between setting the fire and the snowman's head exploding is a way of accurately predicting the weather. The shorter it takes, the "better" (or hotter) the summer will be.

How good is the Böögg at predicting the weather?

Unfortunately, for those who believe in the phenomenon, 2023 is expected to be the worst summer ever. At the event on April 17, the snowman took a record-breaking 57 minutes to explode. However, before we resign ourselves to three months of constant rain, let’s take a look at how accurate the Böögg has actually been in the past.

Sadly, according to Watson and MeteoSwiss, the Böögg has not been an accurate weathervane for the majority of its history. In fact, when the average temperature of each summer is compared with how long the Böögg took to explode each year, the snowman has only been right on a few occasions.

Böögg struggles to predict summer weather in Switzerland

In fact, if a trendline is added, unlike what is taught as part of the tradition, it turns out that statistically the longer the Böögg takes to burn, the better the summer will be - although the differences are marginal. Some notable errors by the snowman include 1968 - when it took just five minutes to explode, but average summer temperatures were just 15,28 degrees celsius - and 1978, when it only took 12 minutes to go, but the summer turned out to be the coldest on record.

On the flip side, climate change has appeared to scupper the Böögg's oracle-like predictions, with 2022, the second hottest summer and the hottest year on record, seeing a time of 38 minutes. According to Watson, the snowman has failed to predict the second, third, fourth and fifth hottest summers on record.

Has the Böögg ever been correct?

However, there are some occasions when the Böögg has been bang on. For example, the sage snowman accurately predicted the hottest summer on record in 2003. That year, the head exploded after just 5 minutes and 42 seconds!

Some other accurate predictions include 2017 - a hot summer with a sub-10-minute explosion time - and 2000 when an average 16,25-minute time was followed by a profoundly average summer.

Sechseläuten continue to be a favourite for Zurich residents

Watson concluded that it is perhaps not surprising that the Böögg is unable to accurately predict the summer, as elements like the structure of the pyre, the moisture of the wood and the weather on the day can have dramatic effects on the time it takes for the snowman to explode. Nevertheless, while it may not be accurate, it’s safe to say that the people of Zurich won’t be giving up their strange tradition any time soon.

Here's a full video of what happened in 2023:

Video: Zurich the best city in the world / YouTube

Thumb image credit: Shutterstock.com / Michael Derrer Fuchs