An ''Extreme'' Report: Increasing societal awareness for today's climate extremes

In December 2025, KNMI published “An Extreme Report: Extreme weather in times of climate change”. The report presents detailed examples of plausible yet currently rare or unseen climate extremes and their potential impacts, aiming to support governments, professional stakeholders, and the public in preparing for present-day climate risks. The storylines cover a wide range of hazards and, where possible, were developed in collaboration with impact partners to link meteorological extremes to societal consequences. This presentation provides an overview of the cases, the methods used, and key challenges encountered during the project. 

Why it matters 

Are densely populated societies such as the Netherlands prepared for plausible but as-yet-unseen climate-fuelled extremes? We argue that proactive preparation is both relevant and necessary, especially because in times of climate change the past – to which society is accustomed- is no longer a good guide for what to expect in the near future. The Netherlands has a strong tradition of national climate scenarios, most recently updated in October 2023, which provide consistent long-term scenarios and a variety of derived products (e.g., change-numbers, maps and timeseries) for planning and stress-testing across sectors. However, these scenarios give limited attention to present-day climate extremes, many of which are already increasing in frequency or intensity due to climate change. An Extreme Report addresses this gap by focusing explicitly on near-term, high-impact extremes. 

Nine unseen (compound) weather and climate extremes 

The report describes nine storylines and their impacts: (1) A prolonged heat episode and the impact on the urban environment, (2) Wildfires and the impact on fire brigade demand, (3) Cold outbreak and the impact on gas demand, (4) Former hurricane hitting the Netherlands and the damage to houses and buildings, (5) Hurricane in the Dutch Caribbean and the damage to houses and buildings, (6) Summer drought and the impact of extremely low Rhine discharge on river transport, (7) Extreme convective rainfall and its impact on the local area, (8) Winter energy drought (“Dunkelflaute”) and the impact on the energy sector, and (9) Mosquitoes and the impact thereof on the emergence of West Nile virus.