Usage — `dwd`

Use-case-driven examples for the dwd CLI, a read-only client for the open DWD Warnwetter app API (warnwetter.de): station forecasts/observations and the published weather-warning feeds (nowcast, municipality/Gemeinde, coastal) plus crowd-sourced reports. Every command prints pretty JSON to stdout, so it composes cleanly with jq.

Install

npm i -g @maschinenlesbar.org/dwd-cli

This installs the dwd binary. Without a global install you can run it straight from a built checkout:

node apps/cli/dist/src/cli/index.js --help

All examples below use the installed bin name dwd.

Use cases

1. Forecast/observation for a single station

Pull the current forecast/observation payload for one DWD station (e.g. München-Stadt, id 10865).

dwd station-overview --id 10865

Output is a JSON object keyed by station id. Each value carries the raw DWD fields (forecast1, forecast2, days, warnings, threeHourSummaries) as scaled integers (tenths of the unit, see GLOSSARY.md). The one change: the API’s missing-value marker 32767 is printed as null — expect null inside the arrays (today’s past hours at some stations, every surfacePressure value at mountain stations), and skip it in sums and averages.

Add --decode for real units — °C, %, hPa, km/h, degrees, mm, minutes of sun — instead of tenths; nothing else changes (timestamps, icon codes, array lengths and alignment):

dwd --compact station-overview --id 10865 --decode | jq '."10865".days[0] | {temperatureMin, temperatureMax, precipitation}'

2. Compare several stations in one call

Fetch multiple stations at once by repeating --id — handy for a small dashboard or a city-vs-city comparison.

dwd station-overview --id 10865 --id 10147

The result is keyed per station, so you can address each independently: jq '."10865"'. An id the API doesn’t know is left out of the answer (exit 0); the CLI names it on stderr, an INFO record of dwd.api: … INFO [dwd.api] no data for station id 99999 — the API answers an unknown id with nothing, not an error.

3. List which monitored stations currently have active warnings

--compact keeps it to one line for scripts; jq surfaces only the stations whose payload contains warnings.

dwd --compact station-overview --id 10865 --id 10147 \
  | jq 'to_entries | map(select(.value.warnings != null and (.value.warnings | length) > 0)) | from_entries'

4. Current nationwide nowcast (short-term) warnings

The nowcast feed is the short-fuse warning layer (e.g. imminent thunderstorms).

dwd warnings nowcast

The feed envelope has a time (publish timestamp) and a warnings array. The CLI adds staleFeed to every warning feed it prints: true when time is more than 60 minutes old (DWD republishes every few minutes, so warnings issued since are missing), with a note on stderr (an INFO record of dwd.api); false otherwise. Count the active entries:

dwd --compact warnings nowcast | jq '.warnings | length'

5. Nowcast warnings in English for a quick triage table

Switch the feed language with --lang en, then flatten event + severity level + description into a compact table with jq. (The feed has no headline/regionName fields; in --lang en only event/descriptionText are translated.)

dwd warnings nowcast --lang en \
  | jq -r '.warnings[] | [.event, .level, .descriptionText] | @tsv'

--lang accepts de (default) or en.

6. Municipality-level (Gemeinde) warnings

The Gemeinde feed resolves warnings down to municipality granularity — the layer the app uses when you select your home town.

dwd warnings gemeinde --lang de

Same envelope shape as nowcast (time + warnings[]). Warnings carry no regionName field (only regions[] geometry), so to find ones mentioning a specific town, search the headline/description text:

dwd --compact warnings gemeinde \
  | jq '.warnings[] | select(((.headLine // "") + " " + (.descriptionText // "")) | test("München"))'

7. Coastal warnings by zone

Coastal warnings (gale/storm-surge style) for boating and the coast. Here the warnings field is an object keyed by coastal zone rather than a flat array.

dwd warnings coast

List the zones that currently carry a warning:

dwd --compact warnings coast | jq '.warnings | keys'

8. Crowd-sourced weather reports overview

The crowd feed is the user-submitted reports overview (meldungen), useful as a ground-truth cross-check against the official warnings.

dwd crowd

Count the submitted reports:

dwd --compact crowd | jq '.meldungen | length'

9. Snapshot a feed to a timestamped file (cron-friendly)

--compact plus a redirect gives you an archivable one-line snapshot per run.

dwd --compact warnings nowcast > "nowcast-$(date +%Y%m%dT%H%M).json"

10. Harden a call behind a flaky network

Tighten the timeout, cap the response size, and identify yourself politely — all global options that apply to any command.

dwd --timeout 10000 --max-retries 3 --user-agent "my-monitor/1.0" \
    --max-response-bytes 5242880 \
    warnings gemeinde

--timeout bounds each attempt, not the whole command: with --max-retries 3 a run can take up to four timeouts plus the waits between them. Bound the whole run from outside if you need to (for example with coreutils: timeout 60 dwd …).

Global options recap

Global options may be given before or after the command — both dwd --compact warnings nowcast and dwd warnings nowcast --compact work.

A base URL on plain http: to a remote host (not localhost, 127.0.0.0/8 or ::1) gets one warning on stderr, a WARN record of dwd.http (… sent unencrypted to <host> (http:, not https:)), before the command’s request; stdout and the exit code are unchanged. Only the base URL the command uses is checked.

Command flags