Clouds are floating masses of condensed water droplets. They are a primary aspect of the weather.
Many strange types of cloud exist in the world.
Types of Cloud
The Imperial Cumulus (積帝雲 Sekitei-un?, Cumuloregalis in the Funimation dub) is an ancient, fossilized mass of clouds that floats around Paradise near the island of Jaya. Its pattern of movement is fairly predictable.
Because of its density, the Imperial Cumulus doesn't have an atmospheric current and can never condense into rain, but it still manages to float in the sky somehow. Additionally, sunlight can't penetrate it, so any area of the Blue Sea caught beneath the Imperial Cumulus will suddenly become dark, almost like it instantly turned from day to night.
Sea Clouds (海雲 Umigumo?), also called Ocean Clouds, are large water-like clouds that form seas in the sky. One can almost sail on it as if it were water, except that Sea Clouds are slightly less dense than water, and as such, things that are dropped into it will sink faster than in normal water. Another difference of seas made of Sea Clouds from seas made of water is that there is no sea floor. However, they still affect Devil Fruit users like a regular body of water would. These clouds form two known seas: the White Sea and the White White Sea.
An artificial type of Sea Cloud that have been shaped into rivers that travel through the air.
Island Clouds (島雲 Shimagumo?) are a special type of cloud. They are fluffy, but dense enough to carry all kinds of things. They form islands in the sky seas.
Like Sea Clouds, Island Clouds are created when a compound in Seastone called "pyrobloin" is ejected into the air by volcanic eruptions and comes in contact with water vapors. The density of the water vapors determines whether a Sea Cloud or Island Cloud will be created.
Satori used a variation known as Surprise Clouds (びっくり雲 Bikkurigumo?) in his Ordeal of Balls. When a Surprise Cloud is touched, you never know what is going to emerge. It could be anything from an explosion to live snakes, though some contain harmless surprises, like flowers.
String Clouds (紐雲 Himogumo?) are clouds that are long and thin like a very fine thread, it is almost invisible, but at the same time has high tensile strength.
Swamp Clouds (沼雲 Numagumo?) are clouds with the qualities of a swamp. Anyone who stands on one of these clouds will sink into it, and the more one struggles, the more they will sink. The Swamp Clouds have no air inside them and victims will end up drowning inside the cloud.
Iron Clouds (鉄雲 Tetsugumo?) are clouds that, as the name suggests, are as strong and durable as iron, while still retaining a clouds weightlessness and ability to change shape.
Due to the power of Soru Soru no Mi, there exist sentient clouds that have special properties and abilities that normal clouds do not possess, including weather manipulation and various lighting-generating abilities.
Flame Clouds (焔雲 Homuragumo"?) are unique clouds created by the power of the Mythical Zoan-type Uo Uo no Mi, Model: Seiryu. The fruit user can use these clouds as foot holds, granting them a pseudo flight. The user can also use these clouds to float other objects, even whole islands. The Artificial Devil Fruit created by Dr. Vegapunk also possesses this ability.
- One Piece Manga and Anime — Vol. 26 Chapter 240 and Episode 154, Pagaya explains creation of island and sea clouds.
- One Piece Manga — Vol. 32 Chapter 303, The cloud from Usopp's Milky Dial is shown to disperse after being released.
- One Piece Manga and Anime — Vol. 29 Chapter 273 (p. 15) and Episode 180, Enel uses a dial to create a Ball Cloud platform.
- One Piece Manga and Anime — Vol. 26 Chapter 246 and Episode 160.
- One Piece Manga and Anime — Vol. 28 Chapter 256 and Episode 164.
- One Piece Manga and Anime — Vol. 28 Chapter 262 and Episode 172.
- One Piece Manga and Anime — Vol. 29 Chapter 268 and Episode 176.
- One Piece Manga and Anime — Vol. 82 Chapter 825 (p. 12) and Episode 784.
- One Piece Manga and Anime — Vol. 82 Chapter 827 and Episode 786.
- SBS One Piece Manga — Vol. 93 (p. 76).
- One Piece Manga — Vol. 99 Chapter 997 (p. 15-17).
- One Piece Manga and Anime — Vol. 69 Chapter 685 and Episode 611.