Final step of the ECMWF Open Data Programme

The broad reach, use and significance of weather and climate information require data and derived products to be communicated effectively, promptly, and without restriction wherever possible. Therefore, open data forms a key part of the ECMWF Strategy. To realise the full potential of open policies, data need to be easily accessible and with the appropriate supporting information to allow users to derive information and form valuable conclusions.    

Since 2020, ECMWF has taken several steps to increase the amount of open data available to its users. Creative Commons licences have been applied to datasets, reducing the cost of data. The data currently released as open data are a subset of ECMWF’s Real-time catalogue at 0.25-degree spatial resolution from both the ECMWF Integrated Forecasting System (IFS) and the Artificial Intelligence/Integrated Forecasting System (AIFS).  

In this talk, we will share our story of how ECMWF Open Data has attracted more users so far, the challenges faced during our transition as well as future planning, and our significant milestone in October 2025. The current ECMWF Open Data is being provided through different mechanisms, all of which have seen a notable growth in usage in the past year: a) The Open Data Portal shows an increase in uptake with 13 TB/day of data downloaded in 2024.  b) Open Charts Service, which provides chart visualisations of ECMWF products.  c) Since January 2022, ECMWF Open Data has also been redistributed by 3rd parties. ECMWF has partnered with different cloud providers as part of their public dataset program. d) The WMO Essential and WMO Additional datasets are still popular.

The 1st of October 2025 marks a milestone in the open data pathway, as ECMWF will then move to fully open data. This means that the entire ECMWF Real-time Catalogue will be under an open (CC BY 4.0) licence. A subset of data will be publicly available via our Open Data Portal for free. However, for the full Catalogue, and services, like area subsetting, customised parameter list or interpolation, users will still have to pay service charges. 

As the open data offering expands, ECMWF will also remove barriers for World Meteorological Organization (WMO) Members by removing all data and service charges for full-resolution data in support of UN initiatives such as Early Warnings for All and the WMO SOFF (Systematic Observations Financing Facility) project. The main objective of the open data pathway is to continue to encourage collaboration, innovation and progress within the meteorological and climate science communities.