Degree day sensor for Home Assistant

configuration.yml

sensor:
  - platform: template
    sensors:
      t81_temperature:
        friendly_name: "Outside Temperature"
        unit_of_measurement: '°C'
        value_template: "{{ state_attr('weather.t81', 'temperature') }}"

      t81_humidity:
        friendly_name: "Outside Humidity"
        unit_of_measurement: '%'
        value_template: "{{ state_attr('weather.t81', 'humidity') }}"
        
      t81_pressure:
        friendly_name: "Outside Pressure"
        unit_of_measurement: 'Pa'
        value_template: "{{ state_attr('weather.t81', 'pressure') }}"
        
      degree_diff:
        friendly_name: "Degree Diff"
        unit_of_measurement: "°C"
        value_template: "{{ ( states('sensor.aqara_bedroom_th_temperature')|float - state_attr('weather.t81', 'temperature') ) | round(1, default=0) }}"
    
      degree_diff_nominal:
        friendly_name: "Degree Diff Nominal"
        unit_of_measurement: "°C"
        value_template: "{{ ( 21.0 - state_attr('weather.t81', 'temperature')|float ) | round(1, default=0) }}"