aurora platform uses the NOAA Aurora Forecast service to let you know if an aurora might be visible at your home location in the next 30 minutes, based off of current solar flare activity.
This service gives a number 0-100 representing the current likelihood of visible auroras at your latitude/longitude. By default this sensor is set up to trigger when the reported likelihood for your location is > 75. It updates every 5 minutes.
You can check the attributes of the sensor to see your exact forecast.
To add the aurora binary sensor to your installation, add the following to your
# Example configuration.yaml entry binary_sensor: - platform: aurora
binary_sensor: - platform: aurora forecast_threshold: 50