Release of the ERA5 'back extension' data (1950-1978) in the Climate Data Store!

UPDATE 02-FEB-2024: The ERA5 preliminary back extension is deprecated and no longer available.

We are pleased to inform our users that the Copernicus Climate Change Service (C3S) at ECMWF has begun the release of the ERA5 back extension data covering the period 1950-1978 on the Climate Data Store (CDS) - see The family of ERA5 datasets.

Although in many other respects the quality of this dataset is quite satisfactory, the current back extension appears to suffer from tropical cyclones that are sometimes unrealistically intense. This is in contrast with the ERA5 product from 1979 onwards (also available from the CDS).

For this reason the current release of the back extension is preliminary.

It is therefore available from separate CDS catalogue entries (hourly, monthly, single level and pressure levels). Around the end of 2021 an updated version of the back extension is to be made available which will be added to the ERA5 catalogue entries that currently reach back to 1979. After an overlap period (the duration of which is not yet decided), the preliminary back extension will be deprecated.

The full back extension preliminary dataset (including model level data on the native grid) is expected to be made available near the end of 2020/early 2021.

We apologize for the delay in our release schedule.

To download the ERA5 data including back extension period, please follow our guidelines on How to download ERA5


C3S Helpdesk at ECMWF


can you already estimate when the final ERA5 back extension 1950-1978 will be released?

Thanks a lot