Global Variables in Home Assistant

There are no global variables in Home Assistant that allow you to store and update data as a list.

 

Where You Can Use Variables

Feature/Section	Can Use Variables	Notes
Automations	✓	Great for triggers, conditions, and actions
Scripts	✓	Especially with variables: block
Templates	✓	Via Jinja2 templating engine
UI (Lovelace)	✘	Variables don’t persist in UI unless part of a custom card
Scenes	✘	Static by design

source:https://blog.usro.net/2025/05/mastering-home-assistant-variables-for-smarter-automations/

 

Note

1.Variables are local to the automation or script

Variables in a script do not persist across automation calls. They’re session-local.

2.Can’t define inside condition,Pre-calculate in variables:

 

 

Limitation	Workaround
globally accessible	Use input_* helpers	detail
Complex types can be tricky	Use json	1.use templating json
Complex types can be tricky	Use dict()

 

 

 

 

useful links

http://localhost:4999/boards/topic/37186/global-variables-in-home-assistant-yaml#56820