average_of_temps_sensor.yaml

# create helper > template > Template a sensor
# put the code below in the State template field

{%- set tempslist = states.sensor
| selectattr('attributes.device_class','defined')
| selectattr('attributes.device_class','in',['temperature'])
| rejectattr('entity_id','search','battery|average|slzb_06')
| rejectattr('state','search','unknown|unavailable')
| map(attribute='state')
| map('float')
| list
-%}
{{ (tempslist | sum / tempslist | length) | round(2) }}