Why is there less/no rain in deserts?

No. Deserts exist for a whole range of reasons. You imply a particular type of desert in the wording of your question. read more

No,there is no such effect of natural crystals which stops the rain to happen in the desert. That is due to the high pressure and low moistured desending arm of Hadley cell which causes deserts to forms near the subtropics.For detailed answe r you can see this video. read more

« Reply #2 on: 17/06/2012 20:29:59 » The soil in some deserts can also be very porous so moisture is not effectively trapped on the surface, which leads to less availability of the moisture to plants, and less evaporation and formation of new rain. read more

It does actually rain occasionally in the Sahara, averaging a few mm/Year only, just not as much as the non dessert land around it. Desserts are formed by a combination of local Geography/Geology and prevailing weather systems. There are far drier places than the Sahara where it hasn’t rained for years, such as the Atacama dessert in south America. read more