Understanding of the importance of medieval astronomy and astrology is often undermined by the assumption that these fields of study were defined in the same way in the medieval period as they are now. It is also often claimed that medieval, Christian theologians were deeply hostile to all forms of astrology. The first part of this paper will show that both these ideas are mistaken, before moving on to outline the rise of weather forecasting by astronomical/astrological methods.
The main part of the lecture will demonstrate the techniques involved in making these predictions and then examine the practice of meteorological record-keeping which was associated with this science. Starting in thirteenth-century Oxford, and continuing through the Astro-meteorological work of Brahe and Kepler, proponents of the science recorded assessments or actual measurements of wind, precipitation, sunshine and temperature, and correlated these against planetary configurations as viewed from their locality. Their aim was to refine their weather predictions by linking them to local climatic conditions. Of course, this proved unsuccessful; but it was nevertheless an important part of the formation of empirically-based weather science.
Anne Lawrence-Mathers is Professor of Medieval History at the University of Reading (UK). She is a Fellow of the Royal Historical Society and of the Society of Antiquaries and served on the Peer Review College of the UK’s Arts and Humanities Research Council (AHRC). She is the author of Medieval Meteorology: from Aristotle to the Almanac (Cambridge University Press, 2020), which was based on research conducted whilst holding a Research Leaders Fellowship funded by the AHRC. Anne is also the author of The True History of Merlin the Magician (Yale University Press, 2012) which explored the importance of Merlin’s roles as a political prophet and reader of the skies. She has written various articles on medieval Computus and calendar science, as well as on meteorology, and is a contributor to the AHRC-funded Expanding Universe research project. This is producing a series of volumes on the scientific works of the thirteenth-century polymath, Robert Grosseteste; and Anne’s particular interest is in the Astro-meteorological treatise attributed to him, the De impressionibus aeris.