Europe Temperatures

Published data were used to analyse the long-term annual temperature trends at twelve locations located in Europe, excluding UK, Ireland and northern Europe.   Stations selected were located in Netherlands, Germany, Switzerland, Austria, Czech Republic, Spain, Malta, Greece, Romania, Ukraine and Belarus.   Similarities in the trends for individual stations enabled a comprehensive trend to be established for the whole region.

The data used were all from the website of KNMI (the Royal Netherlands Meteorological Institute). Only raw data were used (ie as originally recorded, without any adjustments). Data were only used from stations located in rural areas or in small towns so as to avoid the possible influence of urbanisation on the temperatures.

europe-map

 

table-europe

 

The periods of the data ranged from 77 years to 303 years of complete annual data.  The earliest record, at de Bilt, commenced in 1706.

The plots shown below are of the annual mean temperatures at each of the twelve locations. On each plot a polynomial “best fit” trendline has been added. It should be noted that the trendlines near each extremity (ie near the start and end of the records) are quite sensitive to individual data points, whereas trendlines within the main body of the record are much more stable and reliable.

 

COMPARISON OF TRENDLINES

Annual Mean Temperature Trends

[ The basis of these trendlines can be seen from the analyses for the twelve individual stations – see next section.  To avoid congestion and a condensed scale the trendlines are also shown on three separate plots. ]

europe-annual

europe-annual-2

europe-annual-3

europe-annual-4

 

Annual Mean Temperature Residual Trends

[ The individual trend-lines have been adjusted by constant amounts to be approximately zero at trend Lows around 1960. ]

europe-residual

europe-residual-1

 

ANNUAL MEAN TEMPERATURE TRENDS FOR INDIVIDUAL STATIONS

De Bilt (Netherlands ) 1706-2015

debilt

 

Fichtelberg (Germany) 1891-2015

fichtelberg

 

Hohenpeissenberg (Germany) 1781-2015

hohenpeissenberg

 

Saentis (Switzerland) 1883-2015

saentis

 

Sonnblick (Austria) 1887-2015

sonnblick

 

Milesovka (Czech Republic) 1906-1915

 

Mahon/Luis (Spain) 1890-2015

mahonsanluis

 

Luqa (Malta) 1853-2015

luqa

 

Larissa (Greece) 1899-2015

larissa

 

Sulina (Romania) 1876-2015

sulina

 

Askania-Nova (Ukraine) 1910-2015

askanianova

 

Vasilevici (Belarus) 1881-2015

vasilevici

 

 

DISCUSSION AND COMMENTS

  • The data analysed was limited to that which were available on the KNMI website.
  • The annual mean temperature trend-lines for 12 stations can be divided into two groups.  Six stations had well-defined cyclical trend-lines with a High around 1930 and a Low around 1960, with rising trend-lines since then.  The other six stations showed relatively flat trend-lines prior to 1960 but with rising trend-lines since then.
  • Only two of the stations (Mahon/San Luis and Luqa) showed a well-defined high around 2000.  The ten other stations had either an increasing trend-line around 2000 or, at most, a plateau in the trend-line.
  • The increase in temperature from ~1960 to ~2000 was generally 1.0-1.5 deg C.
  • For six stations the temperature reduction from ~1930 to ~1960 was generally 0.3-0.5 deg C.

 

CONCLUSIONS

  • The trend-lines formed two groups, each of six stations
  • For each group the consistency of the annual mean temperature trend-lines of six widely separated stations provides support for the good quality of the data and the conclusions drawn from the analysis.
  • Askania-Nova was, perhaps an exception, having a cyclical trend-line but with no High around 1930.
  • The temperature rise between around 1960 and around 2000 was around 1.0-1.5 deg C.
  • Six of the stations had a cyclical High in their trendlines around 1930 which was generally 0.3-0.5 deg C higher than the Low in around 1960.

 

The Author:

This article was written by Brian Gunter of Narooma, NSW. In his previous life Brian was an engineering hydrologist involved over many years in the analysis of rainfall and river flow data for the planning of water resources projects in Australia, Asia and Africa. In recent years he has been one of the Marine Rescue NSW (previously Royal Volunteer Coastal Patrol) volunteer weather observers who operate the Narooma station for the Bureau of Meteorology.

 

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