I am having trouble downloading the necessary assets for running ai weather forecasting models like PanguWeather. Despite having attained the CDS API key, this is the error I am getting:
ecmwfapi.api.APIException: “ecmwf.API error 1: User ‘’ has no access to services/mars”
requests.exceptions.HTTPError: 400 Client Error: Bad Request for url: https://cds.climate.copernicus.eu/api/retrieve/v1/processes/reanalysis-era5-pressure-levels/execution
invalid request
None of the data you have requested is available yet, please revise the period requested. The latest date available for this dataset is: 2025-03-06 18:00
I am using a simple line of code to request downloading, which what I have found in multiple sites: ai-models --download-assets
Hi! It looks like you’re running into two separate issues.
Problem 1: ECMWF MARS Access Error
ecmwfapi.api.APIException: “ecmwf.API error 1: User ‘’ has no access to services/mars”
This means you’re trying to access ECMWF’s MARS archive using the ecmwfapi, but your account doesn’t have permission. Unless you’re from a Member or Co-operating State or a licensed user, you’ll need to use the CDS API instead.
To get ERA5 via CDS, use the cdsapi with the correct dataset name, e.g.:
reanalysis-era5-pressure-levels → CDS disk subset (fast)
reanalysis-era5-complete → Full MARS archive via CDS API (slower)
Avoid using ecmwfapi unless you specifically are approved for MARS access. To discuss access to MARS, you will need to raise a support ticket via the ECMWF Support Portal.
But if you’re just looking to download ERA5 data, stick to CDS API instead, and you won’t need MARS access.
Invalid Request / Date Out of Range
None of the data you have requested is available yet...
ERA5 data is published with a ~5-day delay. For example, as of today (26-03-2025), the latest available date is 2025-03-21, so you’ll need to adjust your requests to take the delay into account.
Problem 1: ECMWF MARS Access Error
Invalid Request / Date Out of Range