Question

why does a desert cooler cool better on a hot dry day?

Answer 1

Hope it will help u.
A desert cooler cools better on a hot dry day because on a hot dry day temperature is high and humidity is less which helps in better evaporation. Due to the higher rate of evaporation it gives better cooling effect.

Answer 2

Because in a hot dry day there is very low pressure airs and hot airs are very light that is why air cooler do not posses any other pressure while pulling air from its windows because on this day no other air can intrupt it and it will give us maximum air