node-red-contrib-dwd-weatherwarnings

A Node-RED node providing access to the official DWD Weather Warnings (Deutscher Wetterdienst · WARN_L).
The node downloads the latest XML feeds, parses all relevant warning information and exposes a structured JSON payload that is easy to consume in dashboards, notifications and automations.

✨ Features

• Uses official DWD WARN_L weather warning data
• Supports multiple DWD datasets (e.g. commune union, district cells)
• Filtering by warncell ID (single region/cell)
• Optionally returns all active warnings for Germany
• Optional stale mode to keep last valid data on errors
• Auto-refresh support (periodic updates)
• Fetch-on-deploy option for initial data
• Fully i18n-enabled (English / German, including help text and status messages)
• Designed to work together with other DWD nodes (pollen, forecast, rain radar)

📦 Install

From your Node-RED user directory (typically ~/.node-red):

npm install node-red-contrib-dwd-weatherwarnings

Or via the Node-RED Palette Manager:

1. Open the Node-RED editor
2. Menu → Manage palette
3. Tab Install
4. Search for node-red-contrib-dwd-weatherwarnings
5. Click Install

🔧 Configuration

The main configuration options:

Name

Optional display name for the node.
If left empty, a default label is used.

Warncell ID

Optional cell identifier to restrict warnings to a single region.
If left empty, the node can be configured to return all warnings for the selected dataset.

Only active warnings

When enabled, the node filters out expired warnings and only returns those that are currently active.

Allow stale data

When enabled, the node can return the last successfully fetched warning set if the latest fetch fails (for example due to network issues or a temporary DWD outage). A metadata flag indicates that the data is stale.

Fetch on deploy

If enabled, the node performs an initial fetch shortly after the flow is deployed.

Auto-refresh (sec)

Interval in seconds for automatic refresh:

• 0 → disabled (warnings are only updated on incoming messages)
• > 0 → warnings are refreshed periodically

Diagnostics

When enabled, the node writes additional diagnostic messages into the Node-RED log, which helps with debugging and understanding the behaviour.

🔌 Inputs

Any incoming message triggers a refresh of the warning data based on the current configuration, unless the node is already updating due to auto-refresh.

The contents of the input message are not evaluated; the input acts as a simple trigger.

📤 Outputs

The node outputs a message where msg.payload contains warning information.
A typical structure can look like:

{
  "dataset": "COMMUNEUNION_CELLS_STAT",
  "warncellId": "105340000",
  "alerts": [
    {
      "identifier": "2.49.0.0.276.0.DWD.PVW.18594476",
      "onset": "2025-10-28T10:00:00Z",
      "expires": "2025-10-28T18:00:00Z",
      "severity": "moderate",
      "event": "Wind",
      "headline": "Wind warning",
      "description": "There is a risk of gusty winds.",
      "instruction": "Secure loose objects outdoors.",
      "area": {
        "name": "Rhein-Erft-Kreis",
        "code": "105340000"
      }
    }
  ],
  "_meta": {
    "url": "https://opendata.dwd.de/weather/alerts/...xml",
    "count": 1,
    "stale": false,
    "fetchedAt": "2025-10-28T09:45:00Z"
  }
}

The exact output format may differ slightly depending on the implementation, but always follows the idea of a top-level object with:

• the selected dataset and (optional) warncell ID,
• an alerts array with warning objects,
• and a _meta section with technical details.

🔎 Status text

The node uses its status indicator in the Node-RED editor to reflect its current state:

• loading… – currently fetching warnings
• ready – idle, waiting for triggers
• ok – warnings successfully updated (may display number of alerts)
• error – an error occurred while fetching or parsing data
• stale – serving cached warnings due to a recent fetch error

All status texts are fully localised.

🌍 Internationalisation (i18n)

All editor labels, help content and runtime status messages are localised via the Node-RED i18n mechanism.

Translator files:

• English:
  • nodes/locales/en-US/dwd-weatherwarnings.json
  • nodes/locales/en-US/dwd-weatherwarnings.html
• German:
  • nodes/locales/de/dwd-weatherwarnings.json
  • nodes/locales/de/dwd-weatherwarnings.html

The Node-RED editor language (or browser language, depending on configuration) controls which texts are displayed.

🧪 Example flow

A basic example flow is included in:

examples/weatherwarnings-basic.json

It demonstrates:

• manual trigger via an Inject node,
• configuration of the dataset and warncell ID,
• and inspection of the resulting warnings via a Debug node.

Import steps:

1. In Node-RED, open the menu → Import
2. Choose Clipboard
3. Paste the contents of weatherwarnings-basic.json
4. Click Import

🗺️ Roadmap

Planned additions:

• Additional filtering options (e.g. by severity)
• Dashboard-ready example flows
• Combined views with forecast and rain radar
• Optional metrics/telemetry for monitoring

⚖️ License

MIT © 2025 Gerd Rütten

🧰 Changelog

See CHANGELOG.md for the full history of changes.

⚠️ node-red-contrib-dwd-weatherwarnings — bringing official DWD Weather Warnings directly into your Node-RED flows.