DWD Pollenflug (Home Assistant)

Pollen forecast sensors for Germany, sourced from the Deutscher Wetterdienst (DWD) open-data s31fg.json feed — no API key, no rate limit.

A modern, async rewrite of the original hacs_dwd_pollenflug integration.

What you get

• 8 pollen sensors per region: Hazel, Alder, Ash, Birch, Grasses, Rye, Mugwort, Ragweed
• Index 0–3 (transitional bands like 2-3 map to 2.5) for today, with tomorrow and in 2 days plus German descriptions as attributes
• One device per selected region; pick any of the 27 (part-)regions

Why it's different from the original

	Original	This integration
HTTP	requests (blocking)	aiohttp, fully async
Updates	hand-rolled hourly polling + manual per-entity updates	single DataUpdateCoordinator, one fetch shared by all sensors
Poll cadence	every hour	scheduled right after DWD's announced next_update (data changes once/day)
Dependencies	pytz	none (stdlib zoneinfo + HA's aiohttp)
Config	one config entry per region	one entry, multi-region select + options flow
Naming / i18n	raw Pollenflug Graeser 11	has_entity_name + translation keys (DE/EN)
Extras	—	diagnostics, unit tests for the parser

Installation

HACS (custom repository): add https://github.com/NerdySoftPaw/ha-dwd-pollenflug as an Integration, install, restart HA.

Manual: copy custom_components/dwd_pollenflug into your HA config/custom_components/, restart.

Then Settings → Devices & Services → Add Integration → DWD Pollenflug and select your regions.

Lovelace card

A matching Lovelace card lives in its own repository: lovelace-dwd-pollenflug-card. Install it via HACS (category: Dashboard) for automatic resource registration — it ships a GUI editor and a live preview in the card picker, and auto-discovers this integration's sensors.

type: custom:dwd-pollenflug-card
title: Pollenflug – Inseln und Marschen   # optional
forecast: true
entities:
  - sensor.<region>_grasses
  - sensor.<region>_birch
  # ... the other pollen sensors of the region

Sensor state

The state is today's index for that pollen type:

Index	Belastung
0	keine
0.5	keine bis gering
1	gering
1.5	gering bis mittel
2	mittel
2.5	mittel bis hoch
3	hoch

Attributes: state_tomorrow, state_in_2_days, the matching *_desc German texts, plus last_update / next_update.

Development

pip install pytest
pytest tests/            # parser tests, no Home Assistant needed

Data source & licence

Data: Deutscher Wetterdienst, Pollenflug-Gefahrenindex. See the format description (PDF). Integration code: MIT.