This image represents mean global surface temperatures for June 1988 and was derived using data from the High Resolution Infrared Radiation Sounder (HIRS—2) and Microwave Sounding Unit (MSU) carried on a NOAA Polar-orbiting Operational Environmental Satellite. Warmest temperatures are indicated by reds; cooler temperatures are indicated by yellows, greens, blues, and purples, in descending order.