Attribution (required)

The data comes from the open data service of the Deutscher Wetterdienst (DWD), licensed under Creative Commons BY 4.0. The license requires that your users can see where the data comes from. This applies to every plan, including free commercial use.

What to show

Quelle: Deutscher Wetterdienst (English UIs: “Source: Deutscher Wetterdienst”)

• Place it where the data is shown or on a clearly reachable screen (e.g. “About”, “Data sources”), not only in store listings.
• If you modify or combine the data (you do — forecasts are blended and height-corrected), you may add “modified” / “eigene Berechnungen”.
• Link the license where your UI allows links: https://creativecommons.org/licenses/by/4.0/.
• Region geometry (warn cells, municipalities): © GeoBasis-DE / BKG, where you show boundaries.

Examples

<!-- Web footer -->
<p>Wetterdaten: Quelle: Deutscher Wetterdienst,
  <a href="https://creativecommons.org/licenses/by/4.0/">CC BY 4.0</a> (verändert)</p>

// SwiftUI (e.g. under the forecast or on an About screen)
Text("Quelle: Deutscher Wetterdienst (CC BY 4.0)")
    .font(.footnote).foregroundStyle(.secondary)

Warnings are informational

Warnings in API responses are a convenience copy and may be delayed or incomplete. They are not official warnings. Tell your users where official warnings are published: the DWD (dwd.de, WarnWetter app).