Question

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

Answer 1

#ANSWER = A desert cooler cool better on a hot dry day because On a hot dry day, there is high temperature and low humidity. Both these factors are responsible fir increasing evaporation. This also means better cooling

Answer 2

In hot and dry day the moisture level is very low in atmosphere which increases the rate of evaporation. Because of faster evaporation, So, Desert cooler works well.