I'm planning to visit Hong Kong by april 2016, is the weather good during april?

Yes, it can be good to travel in Apr. Usually it is warm then and the temperature ranges from 20C/68F to 28F/82F. It is pleasant to move around. You will meet many cloudy days; showers may happen sometimes, and will stop soon, not influencing your trip. Long-sleeved shirt, light jacket and jeans can be enough.

Personally, it is not the sale season, but you can still get discounts in some malls and markets. You may go for a try and good luck.

Thank you for that very informative answer:)