We are pleased to announce that a new dataset has been published today, 7th August 2026, in the Climate Data Store (CDS):
This dataset is a post-processed version of the original CDS ERA5 hourly data on pressure levels dataset and is stored in Analysis Ready Cloud Optimised (ARCO) format, which has been implemented for retrieving long time-series for a single point in a efficient way.
To generate this ERA5 time-series for a selection of ERA5 variables on a subset of pressure levels dataset, homogenisation conventions have been applied to the ERA5 on pressure levels source GRIB data to ensure consistency, usability, and alignment across chosen variables and time steps. The processed data were then written to an ARCO Zarr archive , enabling efficient cloud-optimised access and scalable data retrieval. Please refer to the user guide for details.
This dataset offers:
- interactive access to the data files using the ERA5 Time-series on pressure levels Download form
- programmatic access to the data files using CDS API service
- programmatic access to the full ERA5 time-series on pressure levels without downloading individual files (analysis-ready Zarr stores) - please refer to instructions provided on the new Analysis Ready Data tab. Please note that this is a Beta service . Data Store Service administrators reserve the right to take the necessary actions at any moment, including closing access to maintain the overall performance of the Data Store Service.
In relation to the new ERA5 time-series data on pressure levels, a NEW “Analysis ready data” tab is now available in the original ERA5 hourly data on pressure levels from 1940 to present data entry. This tab provides instructions including code snippet showing how to open a Zarr store (using xarray) containing the geo-chunked and time-chunked ERA5 hourly on pressure levels data (selected variables on a subset of pressure levels):
https://cds.climate.copernicus.eu/datasets/reanalysis-era5-pressure-levels?tab=analysis_ready_data
For any enquiries regarding this dataset, please contact us (ECMWF login required).
ECMWF Support