English: The Cosmic Microwave Background temperature fluctuations from the 5-year Wilkinson Microwave Anisotropy Probe data seen over the full sky. The average temperature is 2.725 kelvins (degrees above absolute zero; absolute zero is equivalent to −273.15 °C or −459 °F), and the colors represent the tiny temperature fluctuations, as in a weather map. Red regions are warmer and blue regions are colder by about 0.0002 degree.