Get information about pollen in the air at your current location from tomorrow.io.
Got to tomorrow.io, create an account and get your secret key.
Find out your location you want to monitor on pollen.
Test the tomorrow.io service with
https://api.tomorrow.io/v4/timelines?location=<lat>,<lon>×teps=current&fields=treeIndex,grassIndex,weedIndex&apikey=<apikey>
Replace the <lat>, <lon>, and <apikey> with your values.
You should get something like:
{"data":{"timelines":[{"timestep":"current","endTime":"2022-06-19T19:12:00Z","startTime":"2022-06-19T19:12:00Z","intervals":[{"startTime":"2022-06-19T19:12:00Z","values":{"grassIndex":2,"treeIndex":1,"weedIndex":0}}]}]}}
If above test gives you the correct result, then create add an entry to /config/secrets.yaml:
tomorrow-api-pollen: https://api.tomorrow.io/v4/timelines?location=<lat>,<lon>×teps=current&fields=treeIndex,grassIndex,weedIndex&apikey=<apikey>
See secrets.yaml as an example.
Replace the <lat>, <lon>, and <apikey> with your values as done Test.
Create the /config/sensors/tomorrow_pollen.yaml or add these lines to configuration.yaml as shown in: tomorrow_pollen.yaml.
From tomorrow.io you will get a pollen index from 1 to 5. Data can be presented on your dashboard. Look at dashboard.yaml for an example.