Yes, you are right. The weather will be hot and humid during June in Hong Kong. Well, it is OK for you to visit Ocean parks and Lantus Island, but you need to wear cool summer dress and bring
Sunscreen. You'd better also take an umbrella since thunderstorms are norm during this month in HK.

thanks miss iceberg for the useful information! i'm thinking of staying at royal plaza Hk hotel, any feedback about it? what are the must go i should plan in, if its a 3-4days first time trip in HK? will omit disney land this time since i maybe visiting japan & US next few years. will ocean park be crowded in june? any school holidays from 9-12 june?