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Review spring 2021

With a mean temperature of 7.6 °C, spring 2021 was 0.7 degrees too cold overall compared
to the reference period 1961-1990 (March too warm; months of April and May clearly too
cold). If, on the other hand, one refers to the immediate past and also 30-year period 1991-
2020, one obtains a much more significant minus of - 1.85 degrees. A comparison of both
figures with each other expresses the considerable temperature increase due to climate
change in the last 30 years.

Note: Unfortunately, many media and weather reports currently use a new reference period
(1991-2020). This is not wrong in principle, but leads to considerable irritation, because then,
for example, the published anomalies of earlier years are absolutely no longer comparable
with these current data. In times of the rapid climate change that is taking place, it is instead
appropriate to continue to retain the still valid reference period 1961-1990, especially since
this more or less reflects the average temperature conditions in the past 20th century in
Central Europe. In this way, we can recognize and assess the current changes far better. By
the way, the global climate data calculated by NASA in the USA refer unchanged and sensibly
to the alternative reference period 1951-1980, in order to characterize the global climate in
the 20th century in the best possible way.

With a slight increase of 11 hours, we can consider the sunshine duration in spring 2021 to
be about average compared to the reference period 1961-1990. In comparison with 1991-
2020, however, we get a significant minus of 72 hours. Here, analogous to the above-
mentioned facts regarding air temperature, it can be seen that a marked increase can also
be stated for the sunshine duration in the past 30 years.

Moreover, the spring 2021 was too dry with 133 mm in Dresden-Klotzsche (- 24 mm). The
calculated value also almost corresponds to the value measured at our measuring point in
the Intercultural Garden in Coswig (- 21 mm). In comparison with 1991-2020, however, a
weaker minus is obtained (- 8 mm). Spring precipitation thus clearly shows a downward
trend, at least in our region (Fig.1). Trend analyses show that spring precipitation decreased
by an average of about 40 mm during the period 1961-1990.

It should be noted that statements on precipitation should always be treated with caution,
as they vary greatly in space and time. Especially due to local showers and thunderstorms in
the warmer season, striking deviations can be observed again and again. Only observations
over a longer period of time and additional comparisons with neighboring stations and
regions allow largely reliable statements. Thus, the decrease in spring precipitation can be
observed not only in our region, but also in large parts of Germany, whereby especially the
on average increasingly warmer and drier April causes great problems for nature as well as
for agriculture and forestry.

Conclusion: Spring 2021 in the Coswig-Radebeul region was too cold, too dry and about
normal for sunshine.