The KNMI climate dashboard now displays changes in temperature extremes. This includes the number of frost days and the lowest annual temperature. Global warming is associated with a quick decline in cold extremes during winter and a rise in warm extremes during summer. The coldest day of the year is warming nearly twice as fast as the average temperature.
KNMI Climate Dashboard
On the KNMI climate dashboard, you can see how the climate in the Netherlands is changing. It shows changes in temperature, precipitation, drought, wind, fog, sunlight, and sea level. Most measurements date back to the early 20th century. You can quickly see how the recorded values have changed since then.
Initially, we only showed average values, such as the average winter temperature, but now changes in temperature extremes are also visualized. An example is shown in image 1, which depicts the lowest minimum temperature recorded in De Bilt each winter since 1901.
Coldest Day Warms Quickly
Image 1 shows significant variations in the coldest day of winter. The coldest recorded temperature was -24.7°C in 1942, but in the winter of 2014, the temperature did not drop below -3.1°C, a difference of more than 20 degrees! The gray band indicates year-to-year variations. The coldest day occurs outside this band only once every 10 years.
The blue trend line shows that the coldest day of winter has been warming on average since the 1970s, from -11.9°C in 1970 to -9.1°C around 2010. This represents a warming of +2.8°C over forty years, or 0.7 degrees every ten years, which is almost twice as fast as the average winter temperature. The average winter temperature rose by over 0.4 degrees every ten years during the same period (from 2.4°C to 4.1°C).