Additional information: Digital window thermometer with minimum - and maximum indication. This thermometer shows three outside temperature values: the current temperature, and the highest and lowest temperatures that were measured since you last reset it. This convenient thermometer can be attached to the wall using a suction cup. The built-in sensor measures the outside temperature. This thermometer runs on solar energy and measures the temperature ranging from -50 ?C - +70 ?C. Every ten seconds, a measurement is done that is accurate to about 1 ?C.