The 1921 drought was the most severe drought to hit Europe since the start of the 20th century. Here the climatological description of the drought is coupled to an overview of its impacts, sourced from newspapers, and an analysis of its drivers. The area from Ireland to the Ukraine was affected but hardest hit was the triangle between Brussels, Paris and Lyon. The drought impacts lingered on until well into autumn and winter, affecting water supply and agriculture and livestock farming.

At the 14th IEEE International eScience Conference domain specialists and data and computer scientists discussed the road towards open weather and climate science. Open science offers manifold opportunities but goes beyond sharing code and data. Besides domain-specific technical challenges, we observed that the main challenges are non-technical and impact the system of science as a whole.

Around 610K climate station-based observations were rescued over European regions for the main climate variables (maximum and minimum temperature, rainfall, sunshine duration and snow depth) along the 20th century at daily scale in the INDECIS Project. Rescued data will constitute the INDECIS-Raw-Dataset, which will expand current European data coverage contained in the European Climate Assessment & Dataset (ECA&D). The expansion of ECA&D will improve the high-quality of future climate products.

This paper provides a process-based assessment of the impact of spatial model resolution on future projections of European soil moisture changes. In central-western Europe, simulated future drying is more severe and starts earlier in the season at higher global resolution compared to conventional resolution simulations. The enhanced drying suggests that future projections of central-western European drying by conventional resolution global climate models have been potentially underestimated.

Extreme-temperature anomalies such as heat and cold waves may have strong impacts on human activities and health. Providing a robust operational system to monitor extreme-temperature anomalies in Europe, developed and validated in this study, is thus of prime importance. This work exposes the methodology and the climatology of these events. It also discusses the associated uncertainties according to the datasets and the methods used.

On 1 August 1674, very severe thunderstorms occurred along a squall line from northern France to the northern parts of Holland, where damages were particularly severe. Using reported and pictured observations of damages, a reconstruction of this storm is made and an interpretation using modern meteorological concepts is given. Special attention is given to the city of Utrecht, which was hit hardest and where the impact of this storm is still recognisable in the cityscape.

A data set of instrumental pressure and temperature observations for the early instrumental period (before ca. 1850) is described. This is the result of a digitisation effort involving the period immediately after the eruption of Mount Tambora in 1815, combined with the collection of already available sub-daily time series. The highest data availability is therefore for the years 1815 to 1817. An analysis of pressure variability and of case studies in Europe is performed for that period.