The TFA Casa is a digital weather station with an outdoor sensor, allowing you to easily check the indoor and outdoor temperature and humidity level on the digital display. Place the outdoor sensor in a sheltered spot in your garden and the sensor will tell you the outdoor temperature. The sensor and the (indoor) weather station communicate with each other using the same frequency. The weather forecast for the next day is based on (changes in) the air pressure. The time shown on the weather station is radio-controlled, so it's always very accurate. The weather station runs on batteries, so you can place it anywhere.