The first official spring day is right on time this year. That falls on average on March 10. The first official spring day will come a bit later than last year, when it became warmer than 15 degrees in De Bilt for the first time in the year on February 16. The earliest spring temperature ever in De Bilt was measured on January 13, 1993. It was then 15.1 degrees.
First official spring day a fact: measured 15 degrees in De Bilt
