Implementing adequate health preventing measures, which have a positive impact on reducing temperature-attributable mortality (TAM), is essential in public health decision making, particularly in a context of climate change and rising temperatures. Yet, these systems have room for improvement. We identified some of the key aspects that could be refined. Stakeholders emphasised the need of a unified and flexible Pan-European service that provides relevant information. They also highlighted the need to include mortality data to model the real impact of weather. Lastly, end-users demanded that the system was able to produce warnings for multiple lead times beyond the traditionally used 1 to 2 days. Hence, to design prototypes of European weather early warning systems that address these needs, our objective was to study the predictability of temperature-attributable mortality in Europe at the regional scale using weather forecasts with lead times of up to 15 days.

Our main finding is that temperature predictability can be transformed into TAM predictability. Due to the differences in the temperature-mortality associations, significant differences in the TAM predictability are found across the regions. These differences would not be identified if only temperature forecasts were considered. We have seen better predictability in summer for regions associated with a high risk of mortality for summer temperatures. While for winter, better skill is found in regions with a different temperature-mortality association. Although it depends on the region and season, in general TAM can be predicted on weather time scales, as lead times with useful skill are comparable after the transformation of temperature into TAM. In addition, there is a relationship between temperature predictability and TAM predictability, so we presume that future improvement in the weather forecasting will directly lead to improvements in TAM forecasting. More detail can be found on the website heathealth.eu.