A Global ERA5-Based Dataset for Monitoring Drought Occurrence and Impacts

Droughts are intensifying under human-induced climate change, posing increasing risks to ecosystems, water resources, and food security worldwide. Improving the monitoring and characterization of drought occurrence and severity is therefore essential for both scientific understanding and operational decision-making. In this study, we present the ERA5–Drought dataset, a new global, long-term record of meteorological drought indicators derived from the ERA5 reanalysis. The dataset provides both deterministic and probabilistic representations of drought conditions from 1940 to present and is openly accessible through ECMWF’s data infrastructure under a CC-BY 4.0 license.

ERA5–Drought includes two widely used indices: the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI), computed across accumulation periods ranging from 1 month to 48 months. The dataset is complemented by validation metrics to support informed usage and interpretation. Its global coverage and temporal depth enable consistent monitoring of drought variability and trends across diverse climatic regions.

We demonstrate the applicability of the dataset through illustrative case studies in Catalonia (Spain) and Kenya. In Catalonia, long-term time series highlight the evolution and spatial extent of major drought events since 1940, including recent extreme episodes. In Kenya, we show a strong temporal correspondence between meteorological drought conditions and documented socio-economic impacts, such as food insecurity events recorded in the EM-DAT. These examples illustrate how ERA5–Drought can be used not only to characterise hazard, but also to support impact-based analyses when combined with socio-economic data.

The ERA5–Drought dataset provides a flexible and accessible tool for a wide range of applications, from local drought monitoring to global risk assessments. By enabling consistent, data-driven analyses of drought occurrence, intensity, and impacts, it supports environmental agencies, water managers, and agricultural stakeholders in addressing the growing challenges of climate variability and change.