I’m not entirely sure what is being asked here, but the Tigris and Euphrates rivers is the only place in Egypt (besides the nile delta) with non-arid ground. That’s why most people live around there:
See the picture attached above
The answer is; Atmospheric circulation patterns keep the temperature of an area constant.
The atmospheric circulation does not keep the temperatures in an area constant, however, they regulate temperatures through convection currents. Hot air rises as cold air mass sinks to replace the rising hot less dense air. These currents transfer energy around the globe and prevent one area from overheating.