FAQ Tyk Portal


If you have questions that are not answered here, or have suggestions for missed features, you could mail to dataservices@knmi.nl for more information.

Where are the old functionalities from KDC?

With its introduction, the KNMI Data Platform (KDP) will be more primitive and sober than the KNMI Data Center (KDC): it functions as a foundation on which we will continue to build.

This means:

  • No search option for ‘what’, ‘where’ and ‘when’
  • No filtering on Open Data
  • No WMS- and WCS-functionality

Will dropped functionalities return in the new platform? This depends on you. Our goal is to develop functionalities that are/remain used in the future.

Can I still use FTP?

No. How data is downloaded is changed during the migration from KDC to KDP. FTP and HTTP downloads will be replaced by API download. This impacts the way you are currently downloading data.

How can I get my open data files now?

Here you can find some examples on how the new way of obtaining the open data works. These examples are with the anonymous key, which you can substitute with a registered key when needed.

I have lost my personal API key, what can I do?

All requested API keys are sent to you by e-mail. Unfortunately the e-mails often arrive in your spam folder. As a first step you can check your spam folder to see if you can recover the e-mail containing your API key. If you cannot find the email containing the API key, please send an e-mail to dataservices@knmi.nl to revoke the lost API key. You can request a new API key after the old one has been revoked.

What happens when I go over the limits?

You will get back an error response with HTTP code 429.

Can I request a higher rate limit or larger quotas?

Yes, this is possible. You can send an e-mail to dataservices@knmi.nl for temporarily personalized rate limit and quota. Please describe what you need and why you need it.

Why does my API usage not reflect the API calls?

There might be some latency due to updating between your API calls and your API usage

What if my key no longer works?

For the anonymous keys there is a time limit. For more explanation and the new key go to here.
If your own registered key does not work, please contact dataservices@knmi.nl

What are the costs?

All datasets in this portal are free of charge and provided under the ‘OpenData’ policy of the Dutch government. For more information on the ‘OpenData’ policy go to the data portal of the Dutch government.

Why are there limits?

To ensure fair usage and to be able to scale the operation costs of the KDP, an upper limit of requests is set. For unregistered users, these limits will be shared among all users. To qualify for individual limits, you can register with your email address. The following limits on API requests should be suitable for most operational use cases. However, if you are interested in obtaining a large dataset in a short amount of time, you should mail to dataservices@knmi.nl to obtain a specific API key best tailored to your needs.

What about the protection of personal information?

When you provide us your email address, you provide us personal data. Personal data is information that can be used to identify you, like a name, a home address, or an email address. The protection of personal data is codified in law (‘Wet bescherming persoonsgegevens, Wbp’). This law helps to guard the privacy of citizens and is also applicable for personal data collected via the internet.
Under this law, personal data can only be used if it is explicitly stated. It also must be explicitly made clear for what purpose the information is kept. KDC uses your email address only for access registration and provision of access rights to datasets (authentication and authorization purposes). The law does provide some exceptions. The personal data can be used for criminal investigations if someone uses the site for committing acts or making statements which are punishable by law.

I’m not receiving the latest dataset files for a dataset?

If you view the documentation of the Open Data API in the API Catalogue, you can see that the endpoint for listing the dataset files supports the startAfterFilename query parameter. This query parameter can be used to retrieve all files after a specific filename, where UTF-8 binary order is used in filename comparison. If we list the files for the dataset radar_forecast/1.0 without specifying startAfterFilename, we retrieve a list of objects with the following filenames:

 RAD_NL25_PCP_FM_201910261400.h5,  RAD_NL25_PCP_FM_201910261405.h5, RAD_NL25_PCP_FM_201910261410.h5, …

To retrieve the first files on date 2020-01-01, we pass the last valid dataset filename of the previous day as a value to startAfterFilename. In this example, this will be the file with name RAD_NL25_PCP_FM_201912312355.h5. Note that the filename consists of the date, 2019-12-31, and the the time, 23:55. As a suffix, this becomes the value 201912312355. If we call the endpoint for listing dataset files again with RAD_NL25_PCP_FM_201912312355.h5 as value for the query parameter startAfterFilename, we retrieve a different list of objects with the following filenames:

 RAD_NL25_PCP_FM_202001010000.h5,  RAD_NL25_PCP_FM_202001010005.h5, RAD_NL25_PCP_FM_202001010010.h5, …

Now the datasets file “after” the given filename are returned. The documentation of the Open Data API explains in more detail how comparison of the value startAfterFilename with existing dataset filenames works.