Beginning of spring in Hamburg, Germany

Link: https://kaltesonne.de/fruehling-passt-nicht-ins-klimanarrativ-bluete-derhamburger-forsythie-verspaetet-sich-immer-mehr/ Please see link above for source text in German, embedded hotlinks, and comments.

Spring does not fit into the climate narrative: the flowering of Hamburg's forsythia is becoming increasingly late March 28, 2021 from cold sun

By Josef Kowatsch and Sebastian Lüning It feels like spring begins in Germany when the Hamburg forsythia bush blooms in the city center. The location at the Lombard Bridge on the Alster is well suited, because the surrounding area has hardly changed structurally in the last 50 years. The phenologist Jens Iska-Holtz dates the flowering date 2021 to March 25th, 84 days since the beginning of the year. Over the last 50 years the following graphic results:

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Fig. 1: Development of the forsythia bloom in Hamburg since 1972. The years since 1972 are plotted on the X-axis, the flowering date on the Y-axis, measured in days after the beginning of the year, i.e. from January 1st There is no significant trend in the flowering dates of the Hamburg forsythia bush on the Alster. The average is 79 days from the beginning of the year. At 84 days, the start of flowering was slightly above average this year. Earlier flowering dates were a long time ago. Let us now take the new climate reference period 1991 to 2020 as the observation period:

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Fig. 2. Development of the forsythia bloom in Hamburg since 1991. Note: rising trend line means delay. At the beginning of the observation 31 years ago, the forsythia flowered closer to the end of February, the flowering date moved further and further back into March. The last bloom in February was in 2008.

How can the spring delay within the last climate unit, i.e. since 1991 in Germany, be explained? Global warming? Carbon dioxide? The month of February is decisive for the forsythia bloom. The corresponding graphic from the Hamburg weather station for February shows only a slight cooling since 1988.

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Fig. 3: February temperatures in Hamburg since 1988 based on original data from the German Weather Service.

We come to the question of which year the forsythia bloom has been delayed.

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Fig. 4: Since 1985, i.e. for 37 years, the forsythia, the DWD's showpiece shrub for the beginning of spring in downtown Hamburg, has shown a slight delay in flowering by 5/6 days.

The reason for the rising trend line and thus the delay is probably the warm February months of 1988/89/90 at the beginning of the observation period.

Result: The forsythia bloom has been slightly delayed for approx. 37 years - clearly from 36 years of age - although the shrub is located in Hamburg city center, on a warm island. You will probably look in vain for reports on the late trend of the Hamburg spring bloomer in the media.

Anyone reading the Kalte Sonne blog will therefore know more.

See also: https://notrickszone.com/2019/03/23/spring-cooling-hamburgs-forsythiablossoming-whopping-17-days-later-than-30-years-ago/ https://principia-scientific.com/german-springs-arriving-later-wikipedia-caughtfaking/ https://infiniteunknown.net/2017/04/02/german-springs-arriving-later-as-wikipediacaught-whitewashing-disinforming-wikipedia-and-the-hamburg-forsythia-patch/

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