Spring 2021 in Europe: was it really so cold?

U bent hier

#Klimaatverandering , #Weer , #Copernicus

Gepubliceerd op 11 juni 2021

How many conversations have you had over the last few months about how chilly this spring has been? Well, the results are in, and it turns out that although a large swath of the continent was cold compared to the last 30 years, looking further back beyond 1991 shows that spring 2021 was far from record breaking for Europe overall.
Europe

The cold spring weather may have felt especially bitter as it came after several years of warmer-than-average springs, and hot on the heels of a short spell of unseasonably warm weather in late March. But data from the Copernicus Climate Change Service (C3S, implemented by ECMWF on behalf of the European Commission) show that Europe as a whole was actually warmer than the 1981–2010 average for spring, and only 0.5°C below the 1991–2020 average.

Whilst central and northwestern Europe were much colder than average, southeastern and southwestern Europe experienced temperatures close to average. To find a colder spring for Europe as a whole, we only have to go back to 2013, and prior to 2013, we only have to go back a few more years to find similarly cool springs and going further back we find many clearly cooler springs. For central Europe (where the cold was the most pronounced), the picture is the same. Such cold springs – which used to be common – are becoming ever rarer.

Average spring temperature anomalies for Europe* from 1979 to 2021, relative to the 1991–2020 reference period. Data source: ERA5 and EOBS. Credit: Copernicus Climate Change Service/ECMWF/KNMI.

*Defined as land areas within 25°W–40°E, 34°N–72°N

Temperatures varied considerably over Europe during both March and April, but on average were not extreme over the continent during either month. During May, most of Europe experienced slightly below-average temperatures.

  • March was milder than usual over northwestern Europe, colder than the 1991–2020 average over southeastern and far eastern Europe, and close to average over the southwest of the continent. The only regions where temperatures differed from their 1991–2020 averages by more than 3°C were the north of the Svalbard archipelago, where it was relatively mild, and over the far northeast of European Russia, where it was relatively cold.
  • April temperatures were below average across an area sweeping from Iceland to the Mediterranean and Black Seas, with – for example – Germany seeing its coldest April in 40 years, but above average over the west of the Iberian Peninsula and over the far east of the continent. The month began with unusually mild conditions in many places, but temperatures plummeted over an extensive region during the first week, reaching record lows over parts of western and central Europe, for example over Slovenia.
  • As for May, Germany experienced its coldest since 2010 and maximum temperatures for the first three weeks of May in the United Kingdom were some of the lowest on record. There were, however, above-average temperatures in eastern Europe and in southern Spain, Greece, Turkey, and western Norway. In western Russia, daily maximum temperatures exceeded 30°C north of the Arctic Circle.

“Our data do confirm what many of us have suspected – that the last three months have been on average colder than recent springs – but looking at the longer term, they do also show that the temperatures we have experienced this year would have been a regular occurrence 40 years ago,” says C3S Senior Scientist Freja Vamborg. “This demonstrates the importance of objective, unbiased data in monitoring climate change and confirming or contesting what we think we are experiencing.”

Continue reading