The Weather Institute is not in Heart Gold. It is in Ruby, Sapphire, and Emerald.
There is not a weather institute in Pokemon Heartgold, you are thinking of Pokemon ruby, sapphire, and emerald, there is not a weather institute in Pokemon heartgold.
Sorry to say but there is no weather institute in Pokemon soulsilver version
I remember you get it after beating May beside the Weather Institute after you save the people in the Weather Institute
go west of fortree city and then there is going to be a bridge cross it and you will see the weather institute
The Weather Institute is located to the left of Fortree City.
beat the grunts
He is to the west at the weather institute.
the inner chamber
he is in a cave but you have to get the guy at the weather institute to tell you where he is at
you have to catch or kill kyogre
you talk to your Pokemon if they are first in your party and you can see by their expression weather they are happy with you or not. hope this helped :)
Go to the weather institute on route 119 and go to the very top and you ll find him.