Coldest April in 30 years not all bad, says biologist
This April has been the coldest experienced in the Netherlands in the past 30 years. On average this month, temperatures are about three degrees below normal, said Wageningen University biologist Arnold van Vliet to Trouw.
The average temperature for this month will be 6.5 degrees Celsius, Van Vliet estimated. Normally, temperatures in April lie at around 9.8 degrees, and last year April temperatures were about 1.7 degrees above average. An expert from the KNMI said the harsh northern wind is the culprit of this year's cold spell.
“If you look at the ranking of the hottest April months since 1706, this April is ranked 274th, so almost at the bottom”, said Van Vliet.
Vliet studies the seasonal recurring events such as the blossoming of flowers and the migration habits of birds. Warm weather in March lured both plants and animals out of hibernation, yet now the cold weather has stunted their development again.
“The growth of many trees, shrubs and plants has almost come to a standstill”, Van Vliet noted. Last year, plants and animals came out of hibernation around three to four weeks earlier.
The cold weather is not entirely bad said the biologist, “Nature is roughly where it should be. Fifty years ago this was normal.” Low temperatures are most likely to damage fruit trees, such as plum and cherry trees who are more sensitive to the cold.
Animals are less affected by the chilly weather. Experts, for example, counted more bumblebees this year than in 2020.
Van Vliet doubted if all insects will survive the cold and hail as the bumblebees did. “The insects woke up early this year and have to survive. I think that will be done with varying degrees of success.”
For birds, the late development of nature works in their favor. Grass grows slower, causing farmers to mow later. This gives young chicks a better survival chance. Warmer temperatures in February and March gave birds also plenty of caterpillars to snack on.
“But then, the weather shouldn’t be too dry”, Van Vliet warned. “In drought, their food supply, particularly worms crawl deeper into the ground. The true impact this frosty April has on nature will only be seen in hindsight, Van Vliet said. “We won’t find out until later and it’s super interesting.”