KNMI Data Portal deprecation policy

This document details the deprecation policy for various features of the system.

As with any software existing of many components and contributors, features naturally evolve over time. Sometimes we remove features or introduce breaking changes. To warn you about upcoming changes, we use a deprecation policy for APIs and datasets that are subject to change. We provide example scripts that automatically check and log the any deprecation header here .

API deprecation

The sunset phase is the duration between the announcement of an API (version) deprecation date, and the actual deprecation. Our API sunset phase is two months. Once the deprecation date passed, the deprecated API (version) is no longer functional. If you make use of an API that is in its sunset phase, the response header X-KNMI-Deprecation is included in the API response. This header indicates the deprecation date of the API, and where to find more information on this particular deprecation.

An example response header that contains deprecation information is as follows:

X-KNMI-Deprecation: "sunset=2024-06-01T00:00:00Z; info="

Dataset deprecation

We maintain deprecated datasets and dataset versions for a maximum duration of five years, and up till four versions. Responses for API calls for datasets that are marked as deprecated include the X-KNMI-Deprecation header. X-KNMI-Deprecation indicates when (the version of) this dataset becomes deprecated, and where to find more information about the deprecation.


No policy can cover every possible situation. The developer portal is an always evolving system and this document will grow alongside it. In situations where this policy does not fit, we will communicate this through our newsletter and in all relevant release notes.