Reconstructing the 2022 France Hail Events: A Footprint at the Intersection of Science and Insurance

Hailstorms represent a significant weather-related threats to the French insurance industry, as evidenced by the destructive 2022 hail season, which caused insured losses of approximately EUR 5 billion (FA, 2024). Two major outbreaks, linked to low-pressure systems Maya (early June) and Qiara (mid to late June), alone accounted for an estimated EUR 4.5 billion in property and automobile losses. This event ranks among the costliest hailstorms in French history and has reinforced the need for better understanding of hail severity and its impact on insurance portfolios. Given the heterogeneous and localised nature of this peril, accurately capturing hazard intensity and its spatial distribution remains a key challenge in catastrophe modelling.

Traditionally, hailstone diameter reports from the European Severe Weather Database (ESWD) have been used to characterize hail intensity. While valuable, these observations present several limitations when attempting to characterize hail footprints for a catastrophe model. One significant concern is the population bias, as hail reports tend to cluster in more densely populated regions, leading to incomplete and spatially uneven representation of the event footprint (Púčik et al., 2019). Furthermore, maximum hailstone diameter—commonly used as a proxy for severity—reflects only isolated peak values and fails to represent impact from full distribution of hail sizes across a region (Allen et al., 2015). From an insurance perspective, understanding the overall impact to the built environment is more relevant than just the largest hailstone observed. Additionally, hail mainly impacts the roofs of the structure, but wind-driven hail can pose a significant threat to windows and building cladding. Therefore, at Verisk we leverage range of datasets including radar reflectivity, hail observations and client claims data to develop a historical hail footprint that uses total impact energy as the intensity measure, which captures the observed damage patterns more realistically. This study outlines the approach used for developing the 2022 French hail event footprints and discusses several challenges encountered during this process. We also show how well these footprints captures the spatial severity of the event, thereby, enabling our clients to study their claims experience and increase their confidence in understand the hail risk.