How do I clarify it to my youngster? :
When the spring begins
image alliance/dpa
Spring is there, however when did it really begin? That will depend on who you ask. There are at the very least 4 other ways to find out the start of spring, and there are good causes for everybody.
https://www.faz.net/podcasts/wie-erklaere-ich-s-meinem-kind/kindern-erklaeren-wann-der-fruehling-anfaengt-110354547.html