By Erik Kolstad and Joshua Talib

In a surprising and highly appreciated move, ECMWF has announced it will complete its transition to fully open data by 1 October 2025, a full year ahead of schedule. This means that the entire ECMWF Real-time Catalogue—including data from both the Integrated Forecasting System (IFS) and the new Artificial Intelligence Forecasting System (AIFS), both of which are used in ACACIA—will be available at full resolution, with no data costs for users.

This development is particularly significant for ACACIA partners EMI (in Ethiopia), Météo Madagascar, and ICPAC. These have long sought real-time access to ECMWF’s high-quality forecast data but faced financial and licensing barriers. The availability of full-resolution data will greatly strengthen their forecasting capabilities and support ACACIA’s mission to improve resilience to floods and tropical cyclones.

Crucially for ACACIA, this transition aligns perfectly with our focus on sub-seasonal forecasting. Free extended-range forecast data will be a crucial resource as we co-develop tailored forecast products for East Africa and Madagascar.

However, while this transition removes financial barriers, it also highlights the need to ensure that national and regional meteorological services have the capacity and infrastructure to process, interpret, and apply these data effectively. Too often, new tools and datasets are made available without adequate consideration of the practical challenges faced by under-resourced facilities. Through ACACIA’s capacity-building initiatives and close collaboration with partners, we hope to contribute to bridging this gap—increasing the chance of open data translating into real-world impact.

The decision by ECMWF underscores a broader global trend towards open meteorological data, supporting initiatives such as the WMO’s Early Warnings for All. It also stands in stark contrast to recent developments elsewhere—in particular in the US—where the future availability of currently free data has suddenly become less certain.

ECMWF’s leadership in open data ensures that all partners, regardless of resources, can access and use world-leading forecast information. For ACACIA, this is a big step forward in building capacity, enhancing co-production, and ultimately supporting at-risk communities across the region.

Image generated using OpenAI’s DALL·E