At the end of autumn and the beginning of winter, we often complained about the gray weather. Energy prices soared on some days due to a lack of both wind and sun. That has changed little, as the last few weeks have been filled with sunshine. It is even the sunniest start of the year since 1965, the beginning of the measurements.

Especially in March, the sun shines brightly

January was still on the bleak side, with 62 hours of sunshine in De Bilt compared to a long-term average of 68 hours. February was already a lot sunnier, with 106 hours of sunshine in De Bilt against a long-term average of 90 hours. In March, the sun shows no signs of stopping (see image 1). De Bilt counted more hours of sunshine, 145, by March 17 than is average for the entire month of March (139 hours). And a lot of sun is also expected in the coming days.

The total number of sunshine hours from 2025 until March 17 comes to 313 hours. That is an average of 4.1 hours per day, a record. The previous record was in the year 2003, with 305 hours of sunshine.

More sun due to cleaner air and more high-pressure areas

Looking at the top ten sunniest periods up to March 17, it is striking that the first eight places are all occupied by years in this century (see image 2). We also see an increase in sunshine duration over the past 30 years, particularly in spring and summer (in climatology, spring runs from March 1 to June 1). This is due to the fact that the air has become much cleaner, especially at the end of the last century, as well as the more frequent occurrence of high-pressure areas, resulting in fewer clouds in spring. In winter, the change is much smaller.