# New dataset published in CDS: ERA5 hourly time-series data on single levels from 1940 to present **URL:** \ **Category:** C3S - Announcements\ **Tags:** arco, zarr, era-explorer, era5\ **Created:** [18 March 2025 10:00 UTC](https://forum.ecmwf.int/t/new-dataset-published-in-cds-era5-hourly-time-series-data-on-single-levels-from-1940-to-present/11919 "2025-03-18T10:00:26Z")\ **Posts on this page:** 1\ **Showing post:** 7
**Author:** ![Patrick\_Zippenfenig](https://forum.ecmwf.int/user_avatar/forum.ecmwf.int/patrick_zippenfenig/32/777_2.png) [@Patrick\_Zippenfenig](https://forum.ecmwf.int/u/Patrick_Zippenfenig)\ **Post date:** [25 March 2025 09:40 UTC](https://forum.ecmwf.int/t/new-dataset-published-in-cds-era5-hourly-time-series-data-on-single-levels-from-1940-to-present/11919/7 "2025-03-25T09:40:19Z")
Dear ECMWF Copernicus At Open-Meteo, I am tackling similar challenges with a larger range of ERA5 variables and additional datasets, including [ERA5-Land, CERRA, ECMWF IFS HRES](https://open-meteo.com/en/docs/historical-weather-api?models=ecmwf_ifs,era5,era5_land,era5_ensemble,cerra&start_date=2023-01-01&end_date=2023-12-31), and various national weather service datasets. To maximize efficiency, I opted against traditional formats like NetCDF, HDF5, or Zarr, instead developing a novel chunked, compressed format optimized for time-series compression. Benefits include significantly smaller data sizes and faster compression/decompression speeds. The downside is that it’s not yet a widely adopted format, but we are actively developing Python, Rust, Swift, and TypeScript WASM libraries. Open-Meteo is fully [open-data on AWS](https://github.com/open-meteo/open-data) and [open-source](https://github.com/open-meteo/open-meteo). Your engineers are likely encountering similar challenges with handling massive datasets, IO bottlenecks, storage constraints, and memory limitations—issues that will only intensify with ERA5-Land and the upcoming ERA6. If you’re interested in collaborating on converting the entire Copernicus database into a chunked time-series architecture, feel free to reach out! --- _[View the full topic](https://forum.ecmwf.int/t/new-dataset-published-in-cds-era5-hourly-time-series-data-on-single-levels-from-1940-to-present/11919)._