Hi

Rusting of iron only takes place when it comes in touch with the moist air.

Now, Coastal areas has oceans and seas. Because of this, high percentage of moist and cold air is always present in the atmosphere. So rusting of iron takes place very easily in coastal areas

But when we talk about the desert, the climate in the deserts is very hot and is even very dry . So rusting doesn't take place easily here

In short, there is more amount of moisture in coastal areas than the deserts, so iron rusts faster in the coastal parts.


Thankyou