The earth's surface temperature in Phoenix during mid-afternoon can easily exceed 50oC (122oF) (orange areas on the map 1). and go up to over 58oC (136oF) (red areas on map 1). These areas are dry vacant or desert remnants in the urban area. Areas with lower temperatures are typically moist surfaces such as agriculture, irrigated residential, or areas at higher elevations (note yellow to green areas). Nighttime is famous for development of the urban heat island in Phoenix - note the warmer temperatures over 34oC (93oF) in the city core compared to less than 28oC (82oF) on the outskirts of the metro area. Heat is retained by artificial surfaces which slowly release their stored heat from daytime absorption, such as dark asphalt/concrete surfaces, canyon-like street level areas with buildings, etc.
A typical distribution of earth's surface temperature is shown for day (2 pm) and night (2 am) for mid summer in the Phoenix metro area. The temperatures were derived from a satellite platform system that flies by Phoenix twice a day - called the Advanced Very High Resolution Radiometer (AVHRR) system. It shows the mean temperatures per one kilometer square areas. The patterns on the maps have been smoothed cartographically.
Maps courtesy of A. Brazel. Text by A. Brazel
