Weather Institute
From Bulbapedia, the community-driven Pokémon encyclopedia.
The Weather Institute (Japanese: てんきけんきゅうじょ Weather Research Institute) is a weather research building located on Route 119 in the land of Hoenn in Pokémon Ruby and Sapphire and Pokémon Emerald.
On your first trip through Route 119, Team Aqua or Team Magma have invaded the Institute, after information about Kyogre or Groudon, respectively and the rare Pokémon, Castform. The respective team has also blockaded the bridge, preventing you from going any farther. Enter the building and defeat the grunts to receive Castform with the item Mystic Water.
In Emerald, this facility is used to find Groudon and Kyogre after defeating the Elite Four. Simply speak to the meteorologist inside, and he will tell you of unusual weather patterns in certain routes. If he says there is a drought, Groudon slumbers in the Terra Cave. If downpours are coming down, Kyogre awaits you in the Marine Cave. Go quickly to the route the meteorologist specifies, and you'll find yourself in a battle with one of the two legendary Pokémon (note that you can't catch both at the same time; the meteorologist will specify one weather condition and won't say the other one until the Pokémon causing the weather is captured or defeated).
Trivia
A woman west of Pastoria City in Sinnoh says she used to work at the Weather Institute of Hoenn.
