Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Chhatrapati Shivaji Intl to Yongqiang Intl as you normally would.
The rainfall in Mumbai is generally more than the rainfall in Wenzhou. This will continue over the next 2 days.
With an average temperature of 34 °C, peak weather can be found in May. As a traveller, expect to see changes in flight prices during that period. The temperatures in Wenzhou are colder than in Mumbai.