Commercial weather apps lose summary proceedings filed against KNMI in the Netherlands

The Dutch national weather forecasting service (KNMI) faced a lawsuit over their weather app that was revised. The plaintiffs were the major commercial weather app providers in the Netherlands (NVWB). They lost the summary proceedings, and their claims were dismissed by the judge. The revised KNMI app was relatively unknown in the Netherlands up to the court case, and the app saw a major increase in downloads after the ruling. It even became the number one weather app in the Netherlands on the Apple App Store and Google Play Store.

Background

In November 2024, KNMI revised their weather app, with the main focus on providing extreme weather warnings for public safety. The app comes without advertisements, has accessibility features and the source code has been made open-source since January 2025. The app uses the open data provided by their own weather institute. The commercial companies that provide the weather apps in the Netherlands also use the data from KNMI. It is still an ongoing legal debate if the institute would be allowed to use their own data to provide weather predictions, as that role has been filled in by commercial market parties up to 2025. The KNMI seeks to revise the policy for public safety. The commercial parties filed for an injunction of this change with the court.

Lawsuit

The plaintiffs claimed that the revised app caused unfair competition with their commercial apps for weather forecasts, as it is offered as a free app without advertisements, and is publicly funded. That undermines their business model, as their weather apps use personalized advertisements to make a profit on their free versions. The court was not keen on the additional claims the NVWB made, the ruling states the claims would give the NVWB a co-legislative role on state policy, which is unfounded (article 5.17 of the ruling). The court leaves the revision of the policy up to public debate as a political decision. The ruling also states that this change in policy is not sudden, that the resolution to do so goes all the way back to 2022, and that the KNMI had been given the public approval to come up with a new policy proposal since June 2024.

NVWB's response

The plaintiffs were disappointed in the ruling, and a spokesperson gave a short interview on the matter to the press. A transcript is provided along with a side-by-side translation.

Consumer response

Besides the increase in attention for the KNMI weather app, there was also a fierce debate on the case itself. Because these commercial weather apps are also using the KNMI open data for their weather forecasts, which is publicly funded, it raises concerns about how ethical their commercial practice is, especially because of the personalized advertising. Some more direct responses state that if those commercial parties feel threatened, that their business case was not that great to begin with, and they should start innovating again instead of complaining about it.