Long-term mean air temperatures for West Berlin from 1961 through 1980 were available for the first edition of the Environmental Atlas (SenStadtUm 1985). They were used in updating the next edition, in 1993 (SenStadt 1993). Mean values were based on data from 60 daytime and nocturnal measurement trips using a total of 1,000 measurement points, performed from 1981 through 1983 along 24 different routes. The results were integrated into a network of 24 climate stations. Directly measured long-term mean temperature data were available from two of the stations, Dahlem and Tempelhof. Measurements made in 1981 and 1982 were used for other stations.
Data for East Berlin and the nearby surrounding countryside were gathered from June 1991 through May 1992. Fourteen climate stations operated during this period in all of Berlin. Forty nocturnal and 20 daytime measurement trips with approximately 500 measurement points were conducted, all in East Berlin, except along one east-west combined measurement route, from Rahnsdorf to Grunewald. This program was supplemented by 10 daytime and 20 nocturnal measurement trips, which were undertaken on four routes from the city center into the surrounding countryside in order to determine the climatic significance of open areas at the outskirts of town for the affected inner city.
Update of Data Base in 2000
The changes of the use structures in the building stock and also the changed usage of open spaces were expected to cause climatic effects in many places of the city. Another investigation program was therefore processed from September to November 1999 for the classification of the relevant new building and dense-structure areas. The data from 13 climate stations of the TU Measurement Network as well as the Weather Map of the Free University of Berlin were analyzed; three additional stations were built as part of the investigation program. Moreover, during the same time period, 12 nocturnal measurement trips were carried out through representative and structurally changed areas. The air temperature was measured at 2 m of height. For the weighting of the individual measurements for the time periods 1981-‘83 and 1991-‘92, the prevailing wind directions registered simultaneously with with the temperature measurements at Berlin-Tempelhof were made available as 3-hour values by the German Meteorological Service.
For the situation of land use in Berlin as of 2000, all areas with change potentials of city-wide significance, the construction of which had already been realized in 2000, were taken into account, on the basis of the data from the land-use survey conducted by ID 1 of the Senate Department for Urban Development. In order to also be able to incorporate building projects which had already been initiated, areas were also taken into account on which the projects were slated for completion by 2002.