MARS is ECMWF's Meteorological Archival and Retrieval System. The system has the following features:

  • Facilities to archive and retrieve environmental data
  • 24/7 service
  • Batch and interactive modes
  • Large amount of data, both in size and number of items stored
  • Large number of users with different requirements.

Access to the MARS archive requires being an ECMWF registered user. To request an account, please log an issue request with the ECMWF Support Portal. (See CEMS-Flood User Support for guidance).

Detailed documentation of the MARS archive can be found here.


You can access MARS data through the ECMWF Web API. For support and how to use this service, please see documentation here. It is strongly recommended that you familiarize yourself with the use of MARS coding and the data available. The Copernicus Emergency Management Service EFAS data in MARS can be browsed through here: https://apps.ecmwf.int/mars-catalogue/. For a short tutorial and guide to the data, please see the step-by-step guide on the MARS Web page.