The meteorological winter will officially last another two weeks, but now it is already clear: skating is not going to happen. In fact, January and February are likely to be the hottest winter months ever. And as a result, many hay fever sufferers mistakenly think they have a persistent cold.
December was more than 2 degrees too mild and January more than 3, according to measurements from the KNMI, which did not record one ice day. February is going to surpass it:
"If you include expectations until the end of the winter, it becomes clear that January and February together will set a heat record," Wageningen biologist Arnold van Vliet tells NU.nl. "With a little uncertainty, the whole should be around an average 24-hour temperature of 6.8 degrees. That means the very mild winter of 2006-2007 is written from the books."
More than 5 degrees warmer than a winter from the 50s
With 6.8 degrees, January and February would be 3.6 degrees warmer than the average for those months from the period from 1981 to 2010. Van Vliet does a lot of research into the effects of climate change on Dutch nature, and would rather look at something further back.
For example, a good series of nature observations from the period between 1940 and 1968 exists. The average temperature for the two coldest winter months was then only 1.5 degrees. The current January and February are therefore expected to rise 5.3 degrees above that.
Colds turn out to be hay fever
That is not only an extreme difference for skating enthusiasts, but also for Dutch nature. And therefore again for many ordinary Dutch people, without them noticing. Van Vliet tells about friends who think they are dealing with a persistent cold this winter. "Until I ask them about their hay fever. The hazel has even finished flowering, and the air has been full of pollen from the alder for quite some time - much earlier than normal."
Van Vliet also has the statistics on hand: "It is estimated that the Netherlands has between one and a half and 2 million hay fever patients. About 35 percent of them respond to alder pollen. That means that more than half a million people suffer from hay fever this year in the middle of winter, such as sneezing and a stuffy nose. Without having a virus among the members. "
Winters are becoming softer and that has two causes
The official KNMI classification uses the Hellmann number: a measure of the added amount of frost in a winter. According to that method, the last cold winter was that of 1997 (also the last Elfstedentocht). The last 'very cold' winter was in 1985 and the last officially severe winter was that of 1963, when the frost persisted from November to March.
There are two structural causes for the milder winters in the Netherlands, climatologists say. One is the slowly rising global average temperature. The Netherlands has already become 1.7 degrees warmer on an annual basis. Areas where our winter cold comes from are also getting warmer. With north-east winds, therefore, we now get less cold air than in the past.
Watering down 'warm Gulf Stream'
But there is another paradoxical connection to it: the weakening of the "warm Gulf Stream" in the Atlantic Ocean, also as a result of global climate change.
Many people think that this weakening can lead to a considerable cooling, but the real effect is reversed for the Netherlands: an increase in westerly winds and therefore even softer winters, which moreover bring more rain.