Weatheria is an artificial sky island. It appears to be floating on top of a large bubble and it is notable for the study of weather conditions as well as tools that can create various conditions, such as the Wind Knot. The only resident whose name is known is Haredas. Nami was sent here by Bartholomew Kuma during the events of Sabaody Archipelago, and spent two years on the island honing her skills.
The citizens of this country mainly seem to be tall, old men, with long beards who are dressed up as stereotypical wizards. The country seems to lack any law enforcement personnel, with the citizens themselves having to take actions in the event of a crime. However, they all seem to be quite weak and naïve, and are unsure of how to handle crime and violence, though they do have a prison for criminals. This is demonstrated when Nami attempted to steal their technology.
The island is constantly drifting with the wind. Two years after the Battle of Marineford, it went directly over Sabaody Archipelago. It was last seen over the Sabaody Archipelago, causing rainfall above the fourth back-up platoon, ruining their gunpowder in order to assist Nami.
The Wind Knot (風の結び目,Kaze no Musubime?) is a rope with wind-creating properties that is tied three times. Untying one knot results in a light breeze. Untying a second knot brings a strong wind. Untying the last knot summons a squall. In the anime, Nami uses this rope in conjunction with her Perfect Clima-Tact to perform a technique that dispels an oncoming cyclone. Apparently the Wind Knot can be grown along with other knots in a special type of garden called a Weather Garden.
The Weather Ball was the most important invention on Weatheria. It grows in a garden on Weatheria. Nami stole some of the Weather Balls, and when she returns to train in Weatheria, she asks Haredas how they work, and if it could be turned into a weapon. Haredas replies telling her not to say such dangerous words.