On Monday the Netherlands royal hiking federation KWBN advised schools and other organizations to cancel the first night of the annual four evening marches should the weather make it necessary. Meteorological institute KNMI issued a code yellow storm warning for the entire country for Monday and the KWBN calls on participants not to take any risks, NU.nl reports.

The Avondvierdaagse is a four evenings walking event that is particularly popular in the northern parts of the country and in large cities in the west, such as Rotterdam and Den Haag. According to the KWBN, some 600 organizations across the country are taking part this year. In total about half a million kids will take part in the four-day march. About a third of the Avondvierdaagse events start this week, the rest will happen in June. 

For tonight the KNMI forecasts thunderstorms, possibly accompanied by lightning, strong winds and large amounts of rain and hail falling in a sort period. The KWBN therefore calls on organizers to consult with their municipality and the police about whether or not to continue with the event tonight. The organizers must make the decision to continue themselves. "But we advise local organizations not to take risks."

So far organizations in Enschede, Vlaardingen, Hardewijk, Hoogezand-Sappemeer, Meppel, Leeuwarden, Eindhoven, Almere Haven and Almere Stad canceled their events for tonight due to the weather. "We understand that this is probably a disappointment, but we want to rule out all risks", a spokesperson for the Vlaardingen event said to newspaper AD. The Avondvierdaagse twitter account is keeping track of canceled events. 

Events in Amsterdam-Noord and -Oost are still scheduled to continue as planned. 

Participants will still receive their medal if they could not take part in one evening due to weather conditions, according to NU.nl. One or more nights of marching being canceled due to bad weather is not an uncommon occurrence.