The ECMWF has made its entire real-time catalog open to all in the first stage of a multi-year plan to provide more open data.
The catalog is the set of meteorological and oceanographic forecast products that ECMWF produces and publishes in real time.
The decision to open one of the world’s largest meteorological datasets is part of the ECMWF’s strategy to promote open science, international collaboration and climate resilience.
The move shows support for the UN’s Early Warnings For All initiative, enabling societies worldwide to better anticipate extreme weather, protect lives and livelihoods, and build resilience in the face of a changing climate.
Florence Rabier, the ECMWF director general, said, “Today we are unveiling our plan to achieve our full open data status, earlier than anticipated, by providing the complete ECMWF real-time catalog open to all.
“Since 2019, together with the support of our 23 member states and 12 co-operating states, the team has worked very hard to transition our data to be more open, with more datasets becoming FAIR (findable, accessible, interoperable and reusable) and equitable.”
What does ‘open’ mean at ECMWF?
Open means that ECMWF no longer restricts access to its forecast products – they are licensed under Creative Commons (CC-BY-4.0) and can be reused by anyone for any purpose, provided attribution is given.
However, open does not mean every dataset is provided for free, all at once. The catalog is one of the largest in the world. To make access practical and sustainable:
- A free and open subset of the catalog is published online for immediate use at 25km resolution;
- The entire catalog is open under CC-BY-4.0 with no data costs, but delivery of the full high-volume data may involve service charges to cover distribution costs.
This way, ECMWF can ensure that the data is open to all, while keeping access manageable and sustainable for users worldwide.
Later in 2026, the free and open subset will be extended to include its 9km resolution forecasts with a two-hour latency due to the size of the data.
For users requiring faster or more specialized access, only delivery costs will apply, with no charges for the data itself.
Impact of open data in practice
ECMWF has been moving toward a more open data policy since 2018. For example, its data has been used to facilitate a shift toward sustainable energy systems. Renewable energy company DXT Commodities uses ECMWF datasets in its ‘weather-to-power’ models to predict how much solar, wind and hydroelectric can be produced.
The data has also been used to improve preparedness for severe weather. MetDesk has been able to develop accurate road and rail weather models by blending operational data from both ECMWF and the UK Met Office.
In related news, the ECMWF plans to utilize Europe’s first exascale computer for weather prediction