Why are deserts dry?

The circulation of the atmosphere is such that at 30 degrees north and south latitude you have generally sinking motion of what will typically, at that point, be dry air. Chances of rain are very low in those areas. Other deserts can be attributed to more local effects, like that of terrain or geography. read more

The second-largest desert is the Arctic Polar Desert around the north pole. The majority of familiar hot dry deserts form in the “Horse Latitudes”. This is a belt of calm air and sea occurring in both the northern and southern hemispheres between the trade winds and the westerlies. read more

Cold air does not hold as much moisture as warm air, so the weather in these coastal deserts is very dry as well. These deserts are found on the western sides of continents because cold ocean currents tend to form on the west of continents. read more

Deserts are dry because the air above them is lacking moisture. This is caused by rain shadows, moisture sources being too far away, cold ocean currents nearby or the Earth's circulation patterns. Rain shadows occur when air regularly passes over a mountain before it reaches the desert. read more

People commonly associate deserts with hot and arid locations like the Arabian Desert, however precipitation takes the form of either rain or snow. For this reason, the poles constitute the world’s largest deserts. read more