A Millennium of Weather, Winds and water in the Low Countries

In 1995 under the auspices of KNMI the first volume of a series of 6 books was published, where in some 4000 pages the weather in the Low Countries (present-day Benelux) for the period 1000 to present is depicted and classified. In the books1, the course of the weather during both the winter and summer season as well is followed from year to year and placed in a historical context. In summer 2000, Vol. IV, covering the era 1575-1700, will appear which with the non-instrumental period is covered. Vol. V (to be published in 2001) and Vol. VI (2002) will deal with the instrumental period.
The reconstruction of the weather in the Low Countries is based on sources that are related to the area geographically covered by the present Netherlands and neighbouring areas of the southern part of the North Sea; Gt. Britain, Northern districts of France, the downstream basin of the Rhine, Westphalia and Northwest Germany. If relevant, remarkable or extreme weather in Middle Europe or even Northern Italy is also considered.
The major part of the text is devoted to detailed, well-documented, annotated descriptions and analyses of the weather in the past. Numerous compilations and classifications however offer a structured base for further interpretations. Without being complete the following are mentioned: sources per era and per area, climatology per 25 year period, harvest data, ice on major rivers, tree-ring data, classifications of winter and summer temperature, wet and dry seasons, storms and storm surges.
The books are written in the Dutch language and therefore not easily accessible to the international research world. It is for this reason that we present here in a brief overview some of the issues: the historical sources used, pitfalls that threaten dating due to the different types of calendars that were in use and the way the historical evidence could be classified into instrumental winter temperatures.