# ECMWF Open Data

A free subset of ECMWF's real-time global forecasts from its physics model (IFS) and its machine-learning model (AIFS), published as GRIB2 files four times a day on a download portal and mirrored on AWS, Azure and Google Cloud.

- Category: Weather and climate · by European Centre for Medium-Range Weather Forecasts (ECMWF)
- Website: https://www.ecmwf.int/en/forecasts/datasets/open-data
- Live data: yes
- Checked on the official pages: 2026-10-23

## API

- Official API: yes, docs https://www.ecmwf.int/en/forecasts/datasets/open-data
- Key needed: no
- Price: Free; limits: Open-Data Portal limited to between 500 and 2000 simultaneous connections; rolling archive keeps only the most recent 12 forecast runs (about 2-3 days)
- Base URL: https://data.ecmwf.int/forecasts/
- Formats: grib2, json

Example request:

```
https://data.ecmwf.int/forecasts/
```

## Data and license

- Download: https://data.ecmwf.int/forecasts/ (grib2)
- License: CC BY 4.0 plus ECMWF Terms of Use (https://apps.ecmwf.int/datasets/licences/general/); covers The open subset of IFS and AIFS real-time forecast data; dedicated delivery or service agreements may carry charges
- Commercial use OK
- Credit required
- Embedding with conditions
- Quote (api_official): "A subset of ECMWF real-time forecast data from the IFS and AIFS models is made available to the public free of charge." (https://www.ecmwf.int/en/forecasts/datasets/open-data)
- Quote (api_price): "A subset of ECMWF real-time forecast data from the IFS and AIFS models is made available to the public free of charge." (https://www.ecmwf.int/en/forecasts/datasets/open-data)
- Quote (license): "Their use is governed by the Creative Commons CC-BY-4.0 licence and the ECMWF Terms of Use ." (https://www.ecmwf.int/en/forecasts/datasets/open-data)
- Quote (commercial): "This means that the data may be redistributed and used commercially, subject to appropriate attribution ." (https://www.ecmwf.int/en/forecasts/datasets/open-data)
- Quote (attribution): "ECMWF must be acknowledged (attributed) as the source. Attribution must be displayed prominently and include ‘this document/data/output/Results is/are based on data and products of the European Centre for Medium-Range Weather Forecasts (ECMWF)’." (https://apps.ecmwf.int/datasets/licences/general/)
- Quote (embed): "Users must remove attribution if requested by ECMWF." (https://apps.ecmwf.int/datasets/licences/general/)
- Quote (service_charges): "Accessing this data, or arranging for any open data to be delivered directly to you, may be subject to Service Charges and a Service Agreement ." (https://www.ecmwf.int/en/forecasts/datasets/open-data)
- Quote (limits): "access to the Open-Data Portal is currently limited to between 500 and 2000 simultaneous connections ." (https://www.ecmwf.int/en/forecasts/datasets/open-data)
- Quote (rolling_archive): "Data are retained for the most recent 12 forecast runs , corresponding to approximately 2–3 days of forecasts based on the four daily IFS and AIFS cycles (00, 06, 12 and 18 UTC)." (https://www.ecmwf.int/en/forecasts/datasets/open-data)
- Quote (formats): "Products are provided in GRIB2 format unless stated otherwise." (https://www.ecmwf.int/en/forecasts/datasets/open-data)
- Quote (download): "the ECMWF Open Data subset is replicated and available on major public cloud platforms , including Amazon Web Services (AWS) , Microsoft Azure and Google Cloud Platform (GCP) ." (https://www.ecmwf.int/en/forecasts/datasets/open-data)
- Quote (client): "use the ecmwf-opendata Python client, which lets you select the data source (ecmwf, aws, azure, or google)" (https://www.ecmwf.int/en/forecasts/datasets/open-data)
- Quote (resolution): "A finer 0.1° resolution is now published alongside the existing 0.25°, for the IFS streams (the AIFS streams remain 0.25° only)." (https://www.ecmwf.int/en/forecasts/datasets/open-data)

## Rules for an agent

- Use the ecmwf-opendata Python client (pip install ecmwf-opendata) or the AWS mirror instead of scraping data.ecmwf.int; listing a directory with 'Accept: application/json' returns JSON; files are GRIB2, so read them with eccodes, cfgrib or earthkit; only the last ~2-3 days are kept.
- Display prominently that the output is based on data and products of ECMWF, with a link to CC BY 4.0, and say if you changed the data.
- Keep under the portal's connection limit; for heavy use pull from the AWS/Azure/Google mirrors.
- Download what you need within 2-3 days; older runs disappear from the rolling archive.

Human page: https://agentgid.com/resources/ecmwf-open-data/
Source: AgentGid (agentgid.com). Facts are quoted from the site's own pages; check the license page before you ship.