When you go on the opendata link, you got a JSON String. I used the content number for the different region, not like the other variant of this sensor here in this thread, which is using the partregion_id into the content path.
I extract from JSON String, for my region, into a sensor attribute for a template sensor. Like above.
As an example for my region “Westl. Niedersachsen/Bremen” it is the content number “3”:
It may work for some time, but it will fail over time. The data is sorted by the number you choose, but the content may change, if other data will get available.
Right now you have 26 or 27 “content numbers”, if more info from other or new weather stations comes available, they will be added to this file, so the numbering will change.
Tbh I don’t see any advantage at all to simply use a number over an id, that is unique and therefore lasting much longer. 
And you already got where you needed to be to find out the correct partregion_id.
Ok, the problem is, I don’t know how to extract the partregion_id for a REST Sensor, to use it like me 
Where did you see a REST sensor in this component? Oh, you use a REST sensor, you don’t use this component… 
Please, explain a little further what you’re doing or trying to do, shouldn’t be that big of a problem to get what we want out of this json-file.
I am using this, to extract the pollution for my region into the attributes of my dwd_pollen REST-Sensor. And with this sensor I go into a template for the state and icon for each pollen typ.
json_attributes_path: "$.content[3]"
json_attributes:
- region_name
- Pollen
The problem is, what you described, is when the content number change. So I need a way to extract the JSON Path for my region with region_id and not with the content number. It would be nice, when the pollen path is into the sensor attributes of my dwd_pollen sensor. Like now
I tried to extract this over the region_id, but my knowledge about JSON isn’t that big
What I still don’t get, 2nd screenshot.
If I blow this into a new yaml sitting in a sensors directory (using sensor: !include_dir_list sensors/)
why the heck does it moan about:
a) 2 lines in a yaml starting " platform: rest" <== editor moans about that one
b) having a line " platform: rest" and somewhere later " platform template" <== editor moans aswell
HA is something a real lottery, especially if being new with it collection interesting stuff from within this community. Since even if things are marked “solved” this doesn’t mean it’ll work at all.
The worst one was the one mention at pt. a) since the HA editor flagged this RED while the settings>server>check configuration validated it green. Means nice to have such checks but as long as these tend to act as a lottery either the whole configuration is sort of rolling dice.
Just besode the fact that I got everything running by now and simply want to thank for the detailed explanation incl. the one with the content number some lines below. Works like a dream.
Even though the topic is quite old, I wanted to share my slightly improved sensor since I managed to solve the issue of dealing with the array and only picking the item for the partregion_id I’m interested in (by using JSONPath) and not using an unreliable array index which can change.
sensor:
# DWD Pollen, see: https://opendata.dwd.de/climate_environment/health/alerts/Beschreibung_pollen_s31fg.pdf
# (partregion_id=111 for "Oberrhein und unteres Neckartal")
- platform: rest
scan_interval: 3600
name: "DWD Pollen"
resource: https://opendata.dwd.de/climate_environment/health/alerts/s31fg.json
json_attributes_path: "$..content[?(@.partregion_id==111)].Pollen"
json_attributes:
- Erle
- Beifuss
- Ambrosia
- Birke
- Esche
- Hasel
- Graeser
- Roggen
value_template: "{{ value_json.last_update }}"
- platform: template
sensors:
dwd_pollen_erle:
icon_template: "mdi:tree-outline"
friendly_name: "Erle"
value_template: >-
{% set dwd_state = state_attr('sensor.dwd_pollen', 'Erle')['today'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
attribute_templates:
today: >-
{% set dwd_state = state_attr('sensor.dwd_pollen', 'Erle')['today'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
tomorrow: >-
{% set dwd_state = state_attr('sensor.dwd_pollen', 'Erle')['tomorrow'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
You have to replace the 111 in the json_attributes_path of the first REST sensor with your partregion_id. This REST sensor then has one attribute for each pollen type. The second sensor (template type) is just an example, you have to repeat this for every pollen type, it’s sadly quite repetitive. Its value is a number between 0 and 6 (indicating the intensity today) and the attributes contain todays’ and tomorrows’ intensity. So you’re quite flexible with using it in a Lovelace card.
That’s a great snippet to use, thanks a lot!
But as far as I can see, this doesn’t work, does it? 
Either you call the rest sensor “DWD Pollenbelastung” or you change the template sensors from
{% set dwd_state = state_attr('sensor.dwd_pollenbelastung', 'Erle')['today'] %}
to
{% set dwd_state = state_attr('sensor.dwd_pollen', 'Erle')['today'] %}
Either way great contribution!
@dyfcom
I am very sorry, I totally missed your reply and didn’t answer. Sorry for that! Fortunately @rkallensee did a great job with his snippet.
Thanks for the hint - absolutely true. 
I fixed my example.
No Problem, it is still working for me. But! I swith to the great example from @rkallensee and it working like a charm!
Im new to Home Assistant and had my Allergietest today, now i used ur template to add all the Pollen i need, works perfect.
Could u please share ur lovelace card as an example? I dont know how to begin 
Thanks in advance
Just use the entity the template sensor provides. 
To stay with the example from @rkallensee from above, this is your entity:
- type: entity
entity: sensor.dwd_pollen_erle
I am now using a custom integration for it and it works perfectly GitHub - mampfes/hacs_dwd_pollenflug: Adds pollen forecasts from DWD to Home Assistant.
My hope was something nicer than just the entities with the Stat :). And I don’t know how to add the attribute for tomorrow. That’s why I ask.
EDIT: Learning by doing found a way with multiple entity row
Then you should ask for that. 
I answered your request for “a begin”.
But you seem to have found a starting point, that’s the important thing! FWIW here is a part of one of my configs to show the “Pollenbelastung” on one of my tablets.
# Lovelace view
- type: custom:stack-in-card
mode: horizontal
cards:
- type: markdown
content: >
Birkenpollen
- type: custom:bar-card
entity: sensor.dwd_pollenbelastung_birke
name: Heute
height: 20px
icon: none
limit_value: true
min: 0
max: 6
color: *color_lightgrey
severity:
- to: 0
color: *color_lightgrey
- from: 1
to: 2
color: *color_yellow
- from: 3
to: 4
color: *color_orange
- from: 5
to: 6
color: *color_red
positions:
name: inside
indicator: off
icon: off
value: inside
- type: custom:bar-card
entity: sensor.dwd_pollenbelastung_birke_tomorrow
name: Morgen
height: 20px
icon: none
limit_value: true
min: 0
max: 6
color: *color_lightgrey
severity:
- to: 0
color: *color_lightgrey
- from: 1
to: 2
color: *color_yellow
- from: 3
to: 4
color: *color_orange
- from: 5
to: 6
color: *color_red
positions:
name: inside
indicator: off
icon: off
value: inside
- type: custom:stack-in-card
mode: horizontal
cards:
- type: markdown
content: >
Gräserpollen
- type: custom:bar-card
entity: sensor.dwd_pollenbelastung_graeser
name: Heute
height: 20px
icon: none
limit_value: true
min: 0
max: 6
color: *color_lightgrey
severity:
- to: 0
color: *color_lightgrey
- from: 1
to: 2
color: *color_yellow
- from: 3
to: 4
color: *color_orange
- from: 5
to: 6
color: *color_red
positions:
name: inside
indicator: off
icon: off
value: inside
- type: custom:bar-card
entity: sensor.dwd_pollenbelastung_graeser_tomorrow
name: Morgen
height: 20px
icon: none
limit_value: true
min: 0
max: 6
color: *color_lightgrey
severity:
- to: 0
color: *color_lightgrey
- from: 1
to: 2
color: *color_yellow
- from: 3
to: 4
color: *color_orange
- from: 5
to: 6
color: *color_red
positions:
name: inside
indicator: off
icon: off
value: inside
- type: custom:stack-in-card
mode: horizontal
cards:
- type: markdown
content: >
Haselpollen
- type: custom:bar-card
entity: sensor.dwd_pollenbelastung_hasel
name: Heute
height: 20px
icon: none
limit_value: true
min: 0
max: 6
color: *color_lightgrey
severity:
- from: -1
to: 0
color: *color_lightgrey
- from: 1
to: 2
color: *color_yellow
- from: 3
to: 4
color: *color_orange
- from: 5
to: 6
color: *color_red
positions:
name: inside
indicator: off
icon: off
value: inside
- type: custom:bar-card
entity: sensor.dwd_pollenbelastung_hasel_tomorrow
name: Morgen
height: 20px
icon: none
limit_value: true
min: 0
max: 6
color: *color_lightgrey
severity:
- from: -1
to: 0
color: *color_lightgrey
- from: 1
to: 2
color: *color_yellow
- from: 3
to: 4
color: *color_orange
- from: 5
to: 6
color: *color_red
positions:
name: inside
indicator: off
icon: off
value: inside
# template code
- platform: rest
scan_interval: 3600
name: "DWD Pollenbelastung"
resource: https://opendata.dwd.de/climate_environment/health/alerts/s31fg.json
json_attributes_path: "$..content[?(@.partregion_id==XXX)].Pollen"
json_attributes:
#- Erle
#- Beifuss
#- Ambrosia
- Birke
#- Esche
- Hasel
- Graeser
#- Roggen
value_template: "{{ value_json.last_update }}"
- platform: template
sensors:
dwd_pollenbelastung_birke:
icon_template: "mdi:tree-outline"
friendly_name: "Birke"
value_template: >-
{% set dwd_state = state_attr('sensor.dwd_pollenbelastung', 'Birke')['today'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
attribute_templates:
today: >-
{% set dwd_state = state_attr('sensor.dwd_pollenbelastung', 'Birke')['today'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
tomorrow: >-
{% set dwd_state = state_attr('sensor.dwd_pollenbelastung', 'Birke')['tomorrow'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
dwd_pollenbelastung_hasel:
icon_template: "mdi:tree-outline"
friendly_name: "Hasel"
value_template: >-
{% set dwd_state = state_attr('sensor.dwd_pollenbelastung', 'Hasel')['today'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
attribute_templates:
today: >-
{% set dwd_state = state_attr('sensor.dwd_pollenbelastung', 'Hasel')['today'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
tomorrow: >-
{% set dwd_state = state_attr('sensor.dwd_pollenbelastung', 'Hasel')['tomorrow'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
dwd_pollenbelastung_graeser:
icon_template: "mdi:grass"
friendly_name: "Gräser"
value_template: >-
{% set dwd_state = state_attr('sensor.dwd_pollenbelastung', 'Graeser')['today'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
attribute_templates:
today: >-
{% set dwd_state = state_attr('sensor.dwd_pollenbelastung', 'Graeser')['today'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
tomorrow: >-
{% set dwd_state = state_attr('sensor.dwd_pollenbelastung', 'Graeser')['tomorrow'] %}
{% if dwd_state == "3" %}6{% elif dwd_state == "2-3"%}5{% elif dwd_state == "2"%}4{% elif dwd_state == "1-2"%}3{% elif dwd_state == "1"%}2{% elif dwd_state == "0-1"%}1{% else %}0{% endif %}
dwd_pollenbelastung_birke_tomorrow:
icon_template: "mdi:tree-outline"
friendly_name: "Birke Morgen"
value_template: "{{ state_attr('sensor.dwd_pollenbelastung_birke', 'tomorrow') }}"
dwd_pollenbelastung_hasel_tomorrow:
icon_template: "mdi:tree-outline"
friendly_name: "Hasel Morgen"
value_template: "{{ state_attr('sensor.dwd_pollenbelastung_hasel', 'tomorrow') }}"
dwd_pollenbelastung_graeser_tomorrow:
icon_template: "mdi:grass"
friendly_name: "Gräser Morgen"
value_template: "{{ state_attr('sensor.dwd_pollenbelastung_graeser', 'tomorrow') }}"
This gives you six small bars to show today and tomorrow for the three different sensors (in my case Birke, Hael und Gräser). The bar gets coloured from green to red according to the value.
Looks like this (fortunately no values for today 
):
I kinda want to share my janky (and unfinished) approach:
I use the hacs integration to get the entities and I integrate everything into the lovelace like this:
type: custom:vertical-stack-in-card
cards:
- type: glance
title: 'Pollenflug:'
entities:
- entity: sensor.pollenflug_ambrosia
- entity: sensor.pollenflug_beifuss
- entity: sensor.pollenflug_birke
- entity: sensor.pollenflug_erle
show_state: false
state_color: true
- type: glance
entities:
- entity: sensor.pollenflug_esche
- entity: sensor.pollenflug_graeser
- entity: sensor.pollenflug_hasel
- entity: sensor.pollenflug_roggen
state_color: true
show_state: false
To get the custom icons I downloaded the plant icons as svgs from a different integration (for some scandinavian pollen card, but I dont know which one anymore. But thanks to that creator! Here a download for the people who like the icons). I extracted the svgs (added the rye and deleted the allergens that hat no matching sensor). Then I used the custom icon feature of the “Fontawesome icons” integration (created a Folder named “custom_icons” in the config and dropped the svgs in there).
Then I added the following lines in the customize.yaml:
sensor.pollenflug_ambrosia:
icon: fapro:ambrosia
templates:
icon_color: >
if (state === '0') return '#5ebf0f';
if (state === '0.5') return '#a8bf0f';
if (state === '1') return '#bfb10f';
if (state === '1.5') return '#bf900f';
if (state === '2') return '#bf730f';
if (state === '2.5') return '#bf4a0f';
if (state === '3') return '#bf0f0f';
sensor.pollenflug_beifuss:
icon: fapro:beifuss
templates:
icon_color: >
if (state === '0') return '#5ebf0f';
if (state === '0.5') return '#a8bf0f';
if (state === '1') return '#bfb10f';
if (state === '1.5') return '#bf900f';
if (state === '2') return '#bf730f';
if (state === '2.5') return '#bf4a0f';
if (state === '3') return '#bf0f0f';
sensor.pollenflug_birke:
icon: fapro:birke
templates:
icon_color: >
if (state === '0') return '#5ebf0f';
if (state === '0.5') return '#a8bf0f';
if (state === '1') return '#bfb10f';
if (state === '1.5') return '#bf900f';
if (state === '2') return '#bf730f';
if (state === '2.5') return '#bf4a0f';
if (state === '3') return '#bf0f0f';
sensor.pollenflug_erle:
icon: fapro:erle
templates:
icon_color: >
if (state === '0') return '#5ebf0f';
if (state === '0.5') return '#a8bf0f';
if (state === '1') return '#bfb10f';
if (state === '1.5') return '#bf900f';
if (state === '2') return '#bf730f';
if (state === '2.5') return '#bf4a0f';
if (state === '3') return '#bf0f0f';
sensor.pollenflug_esche:
icon: fapro:esche
templates:
icon_color: >
if (state === '0') return '#5ebf0f';
if (state === '0.5') return '#a8bf0f';
if (state === '1') return '#bfb10f';
if (state === '1.5') return '#bf900f';
if (state === '2') return '#bf730f';
if (state === '2.5') return '#bf4a0f';
if (state === '3') return '#bf0f0f';
sensor.pollenflug_graeser:
icon: fapro:gras
templates:
icon_color: >
if (state === '0') return '#5ebf0f';
if (state === '0.5') return '#a8bf0f';
if (state === '1') return '#bfb10f';
if (state === '1.5') return '#bf900f';
if (state === '2') return '#bf730f';
if (state === '2.5') return '#bf4a0f';
if (state === '3') return '#bf0f0f';
sensor.pollenflug_hasel:
icon: fapro:hasel
templates:
icon_color: >
if (state === '0') return '#5ebf0f';
if (state === '0.5') return '#a8bf0f';
if (state === '1') return '#bfb10f';
if (state === '1.5') return '#bf900f';
if (state === '2') return '#bf730f';
if (state === '2.5') return '#bf4a0f';
if (state === '3') return '#bf0f0f';
sensor.pollenflug_roggen:
icon: fapro:roggen
templates:
icon_color: >
if (state === '0') return '#5ebf0f';
if (state === '0.5') return '#a8bf0f';
if (state === '1') return '#bfb10f';
if (state === '1.5') return '#bf900f';
if (state === '2') return '#bf730f';
if (state === '2.5') return '#bf4a0f';
if (state === '3') return '#bf0f0f';
Maybe you can see now where it doesnt work as I hoped. Theoretically the icons should be colored in hues from green over yellow to red with pollen intensity but I couldn’t get the custom coloring to work.
I kinda put this project aside 'til maybe spring when pollen will become a problem, or until I stumble upon a solution. Maybe one of you can help me fix it.
Edit: you have to install custom-ui and remove one = from the code then it works (thanks MangoMC for the troubleshooting)
This is amazing!
With my basic knowledge I think it’s a “=” too much
I got it to work, the only thing u need is install custom-ui from hacs and it works
🤦 Oh man what an oversight. Thanks for the tipp it now works for me as well