If you have a question for which you can’t find an answer here, or if you have a suggestion for a new feature, you can contact us.
You can use the registration form to register an account. You need to provide a valid and permanently working email address.
If you have any trouble with the sign-up page, please contact us to register an account. In the e-mail state your name, organisation (if any) and the reason for requesting an account. We will then review your request and get back to you within 2 working days.
Access to this API has been disallowed means?{
"error": "Access to this API has been disallowed"
}
This response means that the key you supplied in the Authorization header is not valid for the API you called.
The most common causes are:
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The key is sent as-is in the Authorization header, without a Bearer prefix.If none of these apply, contact us and mention which API you called and the email address of your account. Please do not include the key itself in your email.
Everybody using it shares the rate limit and quota of the anonymous key. Clients that are no longer maintained, or that have been abandoned altogether, keep making requests and thereby keep using up that shared capacity, without anybody benefiting from the data.
Replacing the key every year is our way of cleaning those up: only users that are still actively working on their application pick up the new key, which leaves the rate limit and quota available to those who actually need it. This enables us to keep providing anonymous access.
If you don’t want to update the API key yearly, you can register an account with an email address. With this account you can register for APIs.
.nc extension?In KDP context, files with the .nc extension refer to NetCDF files.
NetCDF is a data format that supports the creation, access, and sharing of array-oriented scientific data.
There are different libraries in different programming languages that can be used to load and manipulate NetCDF files. Documentation of these libraries describes how the library can be used in combination with NetCDF files.
If you’ve lost your API key, please contact us to revoke your API key. You can request a new API key after the old one has been revoked.
You will get back an error response with HTTP code 429. Wait before you retry, and increase the waiting time on every following 429. Our fair use policy describes what we expect from your client.
To download a complete dataset, request a dataset bulk key as described in the Open Data API documentation. Download a dataset once and keep it. Re-downloading a complete dataset because it is easier than archiving it locally is not fair use, and bulk keys are issued with a quota adequate for a single download.
There might be some latency due to updating between your API calls and your API usage.
The Open Data anonymous key is subject to an expiry date. Read the Open Data API documentation for more information, and to view the latest active keys.
Your personal API key does not expire, but when in doubt, please contact us.
All datasets on this portal are free of charge (also for commercial use) and are provided under the Wet Open Overheid (Woo) policy of the Dutch government. Providing them does cost money, and the capacity of the platform is shared by all of its users.
That is why we work with API keys, rate limits, and quotas: they keep usage of that shared capacity fair, and they allow us to keep the operational costs of the platform under control.
The fair use policy describes what we consider reasonable use, so that we can keep access open, free, and reliable for everyone.
No. Anything you ship to a browser or a device is public, so your key can be used by anyone and consumes your quota. Proxy the requests through your own backend, keep the key there, and cache the responses. See our fair use policy for more information.
Please see our Privacy Statement.
The quickest and best way is to subscribe to the Notification Service. You receive a message for every new file as soon as it is available, containing the Open Data API URL to download it. That is faster than asking the Open Data API for the list of files, and it saves you from polling: we consider excessive polling of the Open Data API to check for new files as abuse of the KNMI Data Platform. See our fair use policy.
If you cannot use the Notification Service, you can retrieve the latest files with the Open Data API.
The endpoint that lists the files of a dataset sorts them ascending by filename by default, which for most datasets
means that you get the oldest files first.
Add the sorting=desc query parameter to reverse that order, so that the latest files are on the first page and you
do not have to page through the entire dataset to find them.
The list is ordered by filename unless you specify otherwise: use orderBy=lastModified or orderBy=created if you
want the newest files by time rather than by name.
The Open Data API documentation shows examples of these
parameters, and their full description can be found in the technical documentation in the API Catalog.
If you do poll, do not poll more often than the dataset is actually updated: polling a dataset that is updated every 10 minutes once per second gains you nothing. The update frequency of a dataset can usually be found in its metadata.
X-KNMI-Deprecation in my response mean?As with any software, features naturally evolve over time. Sometimes a new version for a feature will be substantially different, causing the old version of that feature to be deprecated. This key notifies the end of this feature, API version, or dataset. This key is only present when the feature is announced for deprecation. More information can be found here .
The fastest way to get new files as soon as they are available is to use the Notification Service. You will receive a message for every new file, which will have the Open Data API URL you can use to download it. We consider excessive polling of the Open Data API to check for new files as abuse of the KNMI Data Platform. See our fair use policy.