“We noticed this especially in the increasing mildness of the winters, which became more and more striking between 1900 and 1939, and surprisingly a series of three severe winters followed”, recalled M. Rodewald few years after the winter 1939/40 had taken reign (Rodewald, 1948). That was widely anticipated, but the term “severe winter” is rather abstract in order to realize the scope and intensity of the situation.

Temperature is certainly the most important feature of winter, and it will receive the bulk of attention when talking about records. But there are other parameters as well, which should be taken into account when analysing a severe winter and trying to identify the role man played for this to occur. Before looking more deeply into this aspect, in the following sections, a brief overview of some temperature and weather observations made during the first winter in WWII will be discussed.

b. Temperature

General Frost served Europe with three cold events of considerable intensity during the winter 1939/40. From a meteorological point of view, there was a fourth cold wave in the first half of March 1940, which can, at least partially, be attributed to the excessive sea ice cover in the Baltic. Presumably, the most stunning was the arrival of the third wave in mid February, which has already been mentioned in the pervious section (C1), and which resulted in temperatures of 9°C to 10°C below mean, across the region between Hamburg and Warsaw, see Fig. C2-2, p. 49
December 1939: All in all, December cannot be regarded as spectacular, at least not in Western and Central Europe .

__In Great Britain the winter started off mildly, but it became cooler during the first fortnight of December. The first cold spell came during the latter half of December 1939.

__On the German coast of the North Sea the first sea ice appeared around December 17 and remained there until the end of the winter.

__In Berlin the winter started with freezing on December 8th.

__A cold wave caught e.g. Gdynia , -17°C; and Klaipeda , -14°C around Christmas time.

__In the last week of the year the temperatures varied strongly at many German stations, but dropped considerably during some nights, for example on December 29th: Aachen , -8°C; Karlsruhe , –18°C; Hanover , -14°C; and Berlin –13°C.

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