Four Independent DMI Weather Alerts in Home Assistant

The evening I built this, the Danish Meteorological Institute (DMI) had two yellow warnings running simultaneously for my area: thunderstorms until 20:00 and high temperature until 18:00. Home Assistant ships a built-in MeteoAlarm integration that should show both — but it can only surface one alert at a time. The other one simply vanishes.

That’s not a configuration mistake. It’s core issue #131045: the integration exposes one binary sensor per region, and when multiple alerts are active, one wins. For a dashboard that needs to distinguish storm, cloudburst, snow and heat, that’s useless.

cap_alerts: one entity per active alert

The fix is cap_alerts — a small HACS custom integration that models alerts on the CAP standard (Common Alerting Protocol) and creates one sensor entity per active alert instead of cramming everything into one.

Install: HACS → Custom repositories → seevee/cap_alerts, category Integration, restart. In the config flow, pick MeteoAlarm as the provider, country DK, then a region filter.

The region trap: “Trekantområdet” doesn’t exist

I live in Kolding Municipality and was convinced my warning region was called “Trekantområdet” (the local “Triangle Region”). It isn’t — it doesn’t exist in MeteoAlarm at all. Denmark has exactly 8 land regions (plus ~20 marine zones):

EMMA_ID	Region
DK001	Nordjylland
DK002	Midt- og Vestjylland
DK003	Bornholm
DK004	Østjylland
DK005	Syd- og Sønderjylland
DK006	Fyn
DK007	Vest- og Sydsjælland samt Lolland-Falster
DK008	København og Nordsjælland

Check the live feed at feeds.meteoalarm.org and search the areaDesc fields for your area instead of guessing. Kolding is DK005.

Gotcha: DMI’s green “no warnings” messages are tagged with every region

The first poll gave me 69 entities — almost all of them “green Rain”, “green Fog”, “green High temperature”. DMI publishes permanent “There are currently no active warnings” statements for every alert type, and they are geocoded with all region codes. They pass through any region filter.

Consequence: filtering by region is not enough. You must filter on awareness_level — level 1 is green (no warning), 2 yellow, 3 orange, 4 red.

Four hazard types as stable binary sensors

The cap_alerts entities are dynamic with hash suffixes (sensor.cap_alerts_meteoalarm_cap_alert_yellow_thunderstorm_8907cd01) and disappear when the alert expires. You can’t hardcode those into a dashboard card. Instead: four template binary sensors — one per hazard — that scan all cap_alerts entities and parse awareness_type/awareness_level from the parameters:

{% set ns = namespace(hit=false) %}
{% for s in states.sensor if 'cap_alerts_meteoalarm_cap_alert' in s.entity_id %}
  {% set p = s.attributes.get('parameters', {}) %}
  {% set lvl = (p.get('awareness_level','0').split(';')[0] | trim | int(0)) %}
  {% set typ = (p.get('awareness_type','0').split(';')[0] | trim | int(0)) %}
  {% if lvl >= 2 and typ in [1, 3] and 'DK005' in (s.attributes.get('geocode_same') or []) %}
    {% set ns.hit = true %}
  {% endif %}
{% endfor %}
{{ ns.hit }}

That’s the state template for binary_sensor.jordrup_wind_warning (created as a Template Helper in the UI — no YAML files). The awareness-type codes: 1 wind, 2 snow/ice, 3 thunderstorm, 5 high temperature, 10/12/13 rain/flooding. I deliberately let thunderstorm (3) count as storm — DMI issues squall-wind warnings as “Thunderstorm”, and a strict wind-only filter would have hidden the active warning that evening.

The four sensors: jordrup_wind_warning (1+3), jordrup_rain_flood_warning (10/12/13), jordrup_snow_ice_warning (2) and jordrup_heat_warning (5).

The ticker card

With stable binary sensors, the dashboard part is trivial. I use AlertTicker-Card, the same rotating ticker that anchors my context-aware home screen:

type: custom:alert-ticker-card
cycle_interval: 6
alerts:
  - entity: binary_sensor.jordrup_wind_warning
    state: "on"
    message: "⚠️ Storm / High Wind Warning"
    priority: 1
    theme: emergency
  - entity: binary_sensor.jordrup_rain_flood_warning
    state: "on"
    message: "🌧️ Heavy Rain / Flash Flood Alert"
    priority: 2
    theme: warning
  - entity: binary_sensor.jordrup_snow_ice_warning
    state: "on"
    message: "❄️ Severe Snow / Ice Warning"
    priority: 2
    theme: warning
  - entity: binary_sensor.jordrup_heat_warning
    state: "on"
    message: "🌡️ Extreme Heat Warning"
    priority: 3
    theme: warning

When I took the hero screenshot, it was rotating between the storm and heat warnings — two independent hazards, simultaneously, each with its own priority. That was the whole point. The card styling follows the same recipe as the rest of my glassmorphism dashboard.

The limitations, honestly

cap_alerts polls every 5 minutes (configurable), so a brand-new warning can lag a few minutes. Region resolution is coarse — DK005 covers all of southern Jutland, not your street (cap_alerts also offers a GPS polygon filter if you want tighter matching). And my sensors trigger from yellow upwards — if you only care about orange/red, raise lvl >= 2 to 3. If you like pairing Danish public APIs with Home Assistant, the same pattern powers my spot-price EV charging setup.