Euro-Climhist – Ways to Weather Hindcasting

Narrative Reports of (Unusual) Weather Events

Philippe de Vigneulles (1471-1526), a winegrower and wine merchant in the French city of Metz, wrote a chronicle in ancient French. He paid particular attention to the development of the vines, the size of the grape harvests and the quality of the must, as his income depended to a large extent on it.
The effects of extreme weather conditions on the vines are illustrated by a passage that Philippe de Vigneulles took from Marot's chronicle: "This year [1437] on 28 September [8 October according to the Gregorian calendar] it was so cold that the grapes in the city-state of Metz and in neighbouring territories froze [on the vines] before they were ripe. They had to be harvested unripe, which had never happened in living memory. Nobody could drink the juice and there was little of it because more than half of the berries were frozen. As a result, the price of wine increased." (translated from German).
In addition to a large number of weather reports from the period between 1315 and 1526, there are 88 phenological observations in the chronicle. Other winegrowers wrote chronicles similar to Philippe de Vigneulles. The chronicle reports on Metz by Philippe de Vigneulles are included in Euro-Climhist. In terms of duration, density and quality of observation, the data from Metz is among the most important evidence for the climate history of the 15th century (Litzenburger 2015).

Renward Cysat (1545-1613) was the head of the Catholic reform ("Counter-Reformation") in Switzerland and at the same time a naturalist in heart and soul. From 1588 until his death, he described the course of the weather and its effects in Lucerne and on the surrounding mountains (Pilatus, Rigi) using quantifying data. Like Wolfgang Haller, he recorded his observations in writing calendars, but these have been lost. However, he listed the daily observations by month in many of his calendars. In his work Collectanea pro Chronica Lucernensi et Helvetiae (Collection for a Chronicle of Lucerne and Switzerland), for example, he notes the wet and cool month of May 1613: "1613 [May] [...] Has had 25 days of rain including 9 days of heavy rain and watery seas day and night. A cool, wet, unhappy, melancholy time from the 14th until the end of the month. The remaining days already, [...], including several cool mornings, 2 days of great heat, but 3 of medium heat" (translated from German). Cysat clearly recognised that it was getting colder in the longer term at the end of the 16th century, although he was not yet familiar with the term "climate" or even "climate change" in the modern sense (Pfister 2013).

The canon Gaspar Bérody (1585-1646) kept a record of the extreme weather conditions in (Lower) Valais between 1610 and 1642 at Saint-Maurice Abbey. In the second half of July 1621, deep snow fell on the alpine pastures, causing many cattle to starve or to be driven to lower altitudes and fed with hay. On 15 August, a procession was held in Saint-Maurice to ask for warm and sunny weather. Years "without a summer" such as 1621 are characteristic of the climate of the "Little Ice Age" (1300 to 1850).

Father Joseph Dietrich (1645-1704) and others kept the monastery's diary between 1670 and 1704. Until the mid-1680s, he recorded extreme weather events such as the wintry character of November 1676: "In this and the following month, there was a severe cruel and by man's memory never experienced cold, from which vastly all the wells froze and there was a severe shortage of water and Lake Zurich froze up to the town [Zürichseegefrörne]. Many mills had to stop grinding and therefore the flour became somewhat dearer (translated from German)". From the mid-1680s onwards, the descriptions become increasingly dense, often comprising several lines and astonishing in their wealth of finely observed details, for example on various cloud shapes (Pfister 1984). Dietrich's diaries in the monastery archive are now fully digitised.

Since 2015, a project supported by the Swiss National Science Foundation (SNSF 2015-2019) and several foundations has been underway to create a complete annotated online edition of his diary and to integrate his weather observations into Euro-Climhist.