From Licensing to Open Access: Designing a Sustainable Transition in Operational Weather Data

2026-05-20

AI Summary

This work proposes a tiered service architecture designed to reconcile compliance with the European Union’s open data policies and long-term operational sustainability. Core weather forecast data are released under a CC BY 4.0 license, while value-added services generate revenue to offset operational costs. The model employs dynamic infrastructure provisioning and an annual iterative evaluation mechanism, progressively reducing revenue targets to facilitate a smooth transition from a licensing-based model to full open access. Within six months of implementation, over 93% of previously paying institutions renewed their service agreements, and downloads of open data increased substantially. These outcomes demonstrate the architecture’s effectiveness in lowering compliance overhead, enhancing global distribution scalability, and ensuring financial sustainability.

Abstract

This translational article documents the European Centre for Medium-Range Weather Forecasts (ECMWF) transition from a restricted data licensing model to open access under CC BY 4.0, completed in October 2025. The policy context included EU open data requirements and alignment with international data exchange frameworks. The transition was implemented through a tiered service model that kept core forecast data open while offering operationally supported delivery as a cost-recovered service. Between 2020 and 2025, ECMWF executed an iterative planning cycle: setting an annual target for revenue reduction, specifying additions to the open tier under that target, provisioning infrastructure, and assessing outcomes to update assumptions. Drawing on internal administrative records (2014 - 2025), we describe design choices, operational constraints, and early outcomes. In the six months following the end of the transition, more than 93% of previously paying organisations retained a Service Agreement, while open endpoint download volumes increased substantially. We discuss trade-offs in defining the open tier (resolution, parameters, schedule), the reduction of compliance overheads formerly associated with redistribution restrictions, and the scalability implications of global distribution. We note an emerging sustainability question as AI-based forecast products become freely available. The early evidence is consistent with the view that a tiered service model can be designed to reconcile open-access obligations with operational sustainability, subject to monitoring over longer contract renewal cycles (typically annual).

Problem

• open access
• weather data
• sustainable transition
• data licensing
• operational sustainability

Innovation

• tiered service model
• open access transition
• operational weather data
• sustainable data policy
• AI-based forecasting