This map displays the minimum observed 2m (6ft) temperature over a given 15 hour period. This elevation (2m or 6ft) is chosen because it gives an idea of the temperatures we experience living on the surface of the Earth while removing the influence of the actual ground temperature. Because the ground conserves heat much better than the air, the ground is warmer than the air when cool weather follows a prolonged period of warm weather and cooler than the air if warm weather follows a prolonged period of cold weather.