This weather forecaster uses patented Self-Calibrating Technology to provide you with a personal weather forecast for the next 12 to 24 hours, as well as displays current readings that it wirelessly receives from the outdoor temperature and humidity monitor. The LCD screen displays indoor and outdoor temperature and humidity in easy-to-read large numbers, and includes a clock that automatically updates for Daylight Saving Time. The backlit display can be set to auto-dim, and also shows dew point, the current date, and barometric pressure, as well as using trend arrows and high and low records for readings to give you a sense of how conditions have been changing. The display is powered by a 5V power adapter (included) and takes 3 AAA alkaline batteries (for backup; optional; not included). The outdoor sensor requires 2 AA batteries (not included).