Monthly review April 2021

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The month of April was significantly too cold compared to the reference period 1961-1990. With
a monthly average of 6.2°C it was the coldest April month since 1980 (-1.8 degrees deviation).
Especially in the last decade of April, numerous frost days occurred in connection with a
persistently very cold northerly flow (Fig.1). Due to the weather constellation (often blocking
weather conditions), we were frequently caught in the direct inflow of Arctic or Scandinavian
cold air.

135 sunshine hours were registered, a minus of 11 hours.

The sum of all single measurements of precipitation reached 27.1 mm in Coswig in April. Thus,
the monthly total corresponded to only 56% of the normal value for April. We thus registered a
second spring month that was clearly too dry. Due to the relatively low temperatures, the topsoil
nevertheless did not dry out to the same extent as in the very warm April months of previous
years. On the other hand, the exceptional drought of the total soil (due to the still strongly dried
out deeper soil layers) remained unchanged in our region.

Incidentally, the long-term forecast for April 2021 published in various media in January assumed a warmer-than-average April in our region. This example is intended to point out the fundamental inadequacy of this type of weather forecasts. They are largely unserious, since they cannot be sufficiently substantiated from the scientific side.

Note: For the assessment of longer-term climate development, we will retain the reference period 1961 to 1990 in agreement with the German Weather Service. The new (also 30-year) reference period 1991-2020 already reflects the striking global or regional warming too strongly. For example, last April's temperature deviation from the 1961-1990 reference period was a moderate - 1.8 degrees; but from the 1991-2020 reference period, it was -3.5 degrees. This means that April has become warmer by an average of 1.7 degrees in our region over the past 30 years in relation to 1961-1990. An extraordinarily strong increase with unmistakable negative consequences in the recent past.