What is a pre-monsoon shower? Is there any distinguishing feature between monsoon and pre-monsoon showers?
Mango showers, or ‘mango rains’, is a colloquial term to describe the occurrence of pre-monsoon rainfall! Monsoon is prevailing wind due to seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea. Usually, the term monsoon is used to refer to the rainy phase of a seasonally changing pattern. They are notable across much of South and Southeast Asia, including India, and Cambodia. 

https://en.wikipedia.org/wiki/Monsoon here is a helpful resource I used!

:)