Global warming should mean that the period of May 11-15 – known as the Ice Saints in Europe – when late spring frosts often occur, would become less frosty over the years. But the opposite has been the case since 1995.
By Die kalte Sonne
Authored by Josef Kowatsch
(Translated and edited by P. Gosselin)
In Germany the five days from the 11th to 15th May are the so-called Eisheilige (Ice Saints). Farmers used to understand “ice” simply as late spring frost, so these are days with frost.
Our question is how have the Ice Saints behaved at various locations across Germany the last 25 years?
Let’s start with Potsdam, the capital of Brandenburg. We take the last 25 years as the period under consideration:
Figure 1: The five Ice Saints days in the state capital Potsdam. They are getting much colder. 2020 was the low point of the last 25 May months. On three days there were night frosts.
At Bad Kreuznach in the Upper Rhine Valley we show a southern Germany station from from Palatinate, a warm sunny region. The DWD Germany National Weather Service weather station is located north, outside the town.
Figure 2: Bad Kreuznach in the Upper Rhine, the trend line of the present day is even slightly lower for the Ice Saints than in Potsdam.
The DWD weather station is located in the Klotzsche suburb, at the airport north of the Saxon state capital.
Figure 3: DWD station Dresden Klotzsche. Ice Saints in the present. The trendline is a little bit lower than Potsdam and the Ice Saints 2020 were among the coldest since 1997.
Goldbach near Bischofswerda in eastern Saxony, a small suburb with about 500 inhabitants.
Figure 4: The Ice Saints 2019 were clearly the coldest, source of data: Station manager Dietmar Pscheidt.
This DWD weather station is located in the Eifel region, near the Belgian border.
Figure 5: Even in the far west of Germany, the Ice Saints outside the cities have become significantly colder. The average of the five calendar Ice Saints days in 2020 was 4.77°C – the second lowest.
The DWD Station Netzstall is located near Nuremberg, well outside the city. The missing value of the year 2000 was interpolated using the neighboring stations at Nuremberg and Nuremberg-Roth.
Figure 6: The village near Nuremberg shows a falling trend line of the five Ice Saints days. 2020 was slightly colder than 2019 and this year was clearly the coldest in the last 25 years.