ECMWF has today (1 October 2025) made its entire Real-time Catalogue open to all, marking the final stage of our multi-year plan to provide open data.
The initiative marks a significant moment in the ECMWF strategy and our commitment to open up one of the world’s largest meteorological datasets, promoting open science, international collaboration, and climate resilience.
By making data openly available, ECMWF is supporting the UN’s Early Warnings for All initiative and enabling societies worldwide to better anticipate extreme weather, protect lives and livelihoods, and build resilience in the face of a changing climate.
Florence Rabier, 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 Catalogue 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 Reuseable) 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 single dataset is provided for free, all at once. The catalogue is one of the largest in the world. To make access practical and sustainable:
- A free and open subset of the Catalogue is published online for immediate use at 25 km resolution.
- The entire Catalogue 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 ensures 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 our 9 km resolution forecasts with a 2-hour latency due to the size of the data.
For users requiring faster or more specialised access, only delivery costs will apply, with no charges for the data itself.
Impact of open data in practice
ECMWF has progressively moved towards an open data policy since 2018. However, its data has long been driving innovation and efficiency across sectors, creating a safer and more resilient society.
For example, ECMWF’s data is supporting the shift towards sustainable energy systems. Renewable energy company DXT Commodities uses ECMWF datasets to feed its “weather-to-power” models to predict how much solar, wind, and hydroelectric energy can be produced. These predictions are key to balancing renewable energy with other energy sources, ensuring the grid remains stable and reliable.
ECMWF’s ensemble model, in particular, has proven effective at minimising errors in predicting solar and wind production.
Our data is also helping to protect lives by improving preparedness for severe weather. MetDesk, has developed highly accurate road and rail weather models by blending operational data from both ECMWF and the UK Met Office. These models help to mitigate the risks posed by extreme weather events.
ECMWF’s open data policy eliminates barriers to accessing its highly valuable data, allowing scientific, commercial and operational users worldwide to benefit, fostering new innovations, and strengthening resilience.
A unique relationship with the 35 nations behind ECMWF
Over the past 50 years, substantial support has been invested in ECMWF from its Member States, who are at the heart of every decision, ensuring ECMWF delivers a wide range of benefits.
Florian Pappenberger, Director-General elect, said: “Together with Member and Co-operating States, we innovate and co-develop products, share best practice through training and invest in new initiatives and technologies to produce and distribute even higher rates of data.
"The European Weather Cloud (EWC) is a great example of new technical capabilities that we foster. This provides, for example, computing resources and unique software tools to facilitate deployment of machine learning models and this also allows them to expand services to their own citizens. Through their investment in ECMWF, Member States also access High Performance Computing capabilities, in proportion of 25% to 50% of these resources, including a newly acquired set of GPUs essential to train AI/ML models.”
Access the full catalogue and attribution
The entire ECMWF Real-time Catalogue is available under a Creative Commons CC-BY-4.0 licence, allowing the re-use and redistribution of data for research and commercial purposes.
Available free and open datasets:
- ECMWF Open IFS Data
- ECMWF Open AIFS Data
- S2S Data (sub-seasonal range)
- TIGGE Data (research ensemble)
- ERA5
- ECMWF Seasonal Forecast via the Climate Data Store
Importance of attribution
With the move to open data, ECMWF is highlighting the importance of attribution.
Emma Pidduck, Data Policy and Partnerships Coordinator at ECMWF, explained: “Users of ECMWF’s open data sources understand that attribution is really important. It not only adds credibility and value to their work as ECMWF is a trusted source of information, but also supports continued public investment in open, high-quality forecasting that our Member and Co-operating States make in the organisation.
“Additionally, it helps ECMWF discover and share the innovative ways the user community is using our data and demonstrates the value of the Centre’s work to decision makers and further develop our products and services.”
Under the CC-BY-4.0 licence, attribution is a legal requirement. An example attribution could be:
“'Adapted from “ECMWF IFS 15-day Forecast Data'” by ECMWF, licensed under CC BY 4.0, available at https://data.ecmwf.int/forecasts/”