The sun has never shone as much in the first half of a year as in 2025. The record fits into a trend that has been visible in recent years and is a result of the decrease in air pollution and a warmer climate, according to Weerplaza.
Since the beginning of this year, the Netherlands has recorded 1,181 hours of sunshine. Never before have so many hours of sunshine been measured in the first half of the year. Because it will also be sunny in the coming days, that record will be further sharpened.
The previous record dated from 2022, and the one before that from 2020. That sunny trend is caused by cleaner air on the one hand and climate warming on the other. “The cleaner air weighs the most in this,” says Jaco van Wezel of Weerplaza. “The decrease in pollution leads to fewer foggy days.”
Since the 1990s, there has been a clear decrease in particulate matter in the air in the Netherlands. This leads to less fog and more sun. If there is particulate matter, those particles reflect solar radiation and heat back into the atmosphere.
A second explanation for the increase in the number of sunny days is climate change. The link there is indirect. A warmer climate leads to longer periods of drought. And in drought, such as this spring, there is less moisture to evaporate and therefore less cloud formation.
The months of March, April and May made the biggest contribution to the sun record this year. The sun also shone remarkably in February. 2025 has so far counted only 38 ‘very gloomy’ days, on which the sun is visible for less than 20 percent of the daylight period. Those gloomy days mainly fell in January this year.