Netherlands sets new sunshine record in first half of 2025 with 35°C expected on July 1

The Netherlands experienced its sunniest first half of a year on record in 2025, surpassing previous benchmarks by a significant margin. This period will end with approximately 1,245 hours of sunshine, far exceeding the average, which was largely attributed to a decrease in air pollution and changing cloud patterns. Monday should see a high temperature of around 32 degrees Celsius, with Tuesday even reaching about 35 degrees.

The previous record of 1,181 hours of sunshine was set in 2022, a record which has already been broken this year, according to weather website WeerOnline. Their forecasters predict the final figure for 2025 should add about 60 more hours to the tally by the end of Monday. The total number of hours of sunshine for the first six months of this year will wind up nearly 29 percent higher than the average of 966 hours.

This is despite predictions for periodic cloud cover and rain anticipated over the coming week. Wednesday is expected to be partly cloudy with a high temperature ranging from 22 degrees Celsius in Noord-Holland, 23 degrees in Friesland, 25 degrees in Utrecht, 27 degrees in the east and south, and 29 degrees in Limburg, according to the national meteorology office KNMI.

Thursday is expected to be with a 70 percent chance of precipitation, especially in the east of the country, with a high temperature from 21 to 25 degrees. A sunnier, warmer period is expected from Friday through Sunday, as the afternoon temperature begins to climb back up to into the high-twenties.

The month will end with an incredibly sunny Monday where the mercury will climb to between 28 degrees in the north and 32 degrees in the south. Tuesday will be even hotter, with the second half of the year getting underway with the entire country in the low-to-mid thirties. The current July 1 record of 33.1 degrees was set in 2015. National weather records in the Netherlands are measured at KNMI headquarters in De Bilt, Utrecht, considered a climate average for the country.

The spring months of March, April and May were instrumental in breaking the record, contributing 796 hours of sunshine compared to an average of 578. March itself was exceptionally sunny, with 247 hours against its usual 150. February also saw ample sunshine, and June is expected to add about 270 hours, securing a top-ten spot for the sunniest Junes on record. January was the only month to fall slightly below its average sunshine hours.

Beyond overall duration, 2025 also set a new record for "very sunny days," defined as days with at least 80% of daylight hours featuring sunshine. The country recorded 48 such days, surpassing the previous record of 43 set in 2022. This number is expected to climb to 50 or 51 by the end of June, roughly double the usual 27 very sunny days.

Conversely, the number of very gloomy days, with less than 20% of daylight hours seeing sun, was not a record low but remained remarkably low at 38 days. This is significantly less than the normal average of 65 gloomy days, further highlighting the overall bright start to the year.

A warming climate contributes to more cumulus clouds rather than widespread cloud cover, allowing more sunlight to filter through. This shift in cloud patterns plays a significant role in the increased sunshine hours. At the same time, the KNMI noted that air quality in Europe has become cleaner over the past four decades. "The cleaner air is good news for health, but it also affects the weather and climate. There are fewer clouds and less fog, and more sunshine," the KNMI said.

The office noted last week that there has been an overall reduction in particulate matter in the air. This can include desert sand, sea salt, and pollen, which reflects sunlight away, but also soot, which absorbs sunlight. Increased aerosolized particulate matter also leads to more cloud cover and even fog, as can be see just after New Year's Eve when pollution from fireworks brings visibility as low as 50 meters in parts of the country.

"In terms of particulate matter, the air in the Netherlands has become much cleaner in recent decades," the KNMI said, citing data from national and regional health offices. A reduction in aerosols means clouds are not created as easily because water vapor has a reduced chance of clinging to particulate matter in the air.

Thus, "the number of hours with fog is steadily decreasing, while the number of hours with good visibility is increasing," the KNMI said. "The number of hours of sunshine has also increased considerably since the 1980s."

This century has seen a notable increase in extreme sunshine during the first half of the year, with all top ten sunniest periods falling within this timeframe. The trend toward sunnier conditions is primarily linked to reduced air pollution, which has led to less mist formation in the spring, WeerOnline stated.