Home Assistant Blueprint - Inform in case window is open and the temperature becomes below a specific value. Or inform when you open a window and it's already freezing cold.

window-open-temperature.yaml

blueprint:
  name: Window Open Warning
  description: Inform users when windows are open and the temperature is dropping too much.
  domain: automation
  input:
    temp_sensor:
      name: Temperature Sensor
      description: Temperature Sensor to check.
      selector:
        entity:
          domain: sensor
          device_class: temperature
    min_temp:
      name: Minimum Temp
      description: If temperature is below this value, notify people.
      default: 15
      selector:
        number:
          min: 5.0
          max: 25.0
          step: 1.0
          mode: slider
    window_sensor:
      name: Window / Door Sensor
      description: Window Binary Sensor to check if opened. Entity can also be a group of window/door entities.
      selector:
        entity:
    actions:
      name: Actions when it's too cold
      description: Actions (e.g. pushing a notification, TTS announcement, ...)
      selector:
        action: {}
variables:
  window_sensor: !input window_sensor
trigger:
- platform: homeassistant
  event: start
- platform: event
  event_type: automation_reloaded
- below: !input min_temp
  entity_id: !input temp_sensor
  platform: numeric_state
- platform: state
  entity_id: !input window_sensor
  to: 'on'
condition:
- below: !input 'min_temp'
  entity_id: !input 'temp_sensor'
  condition: numeric_state
- condition: state
  entity_id: !input 'window_sensor'
  state: 'on'
action:
- choose: []
  default: !input 'actions'
mode: single