Biome



A biome is a region in a world with distinct geographical features, flora, heights, temperatures, humidity ratings, and sky and foliage colors. Biomes separate every generated world into different environments, such as forests, jungles, deserts, and taigas.

Temperature
Biomes have a temperature value that determines if it snows or rains. The required temperature values are less than 0.15 for snow, and above 0.15 for rain. The temperature also drops 0.0016 ($1/625$) per meter above the default sea level (Y=64), but does not change below sea level. These values can be used to determine the heights that snow generates at in different biomes. For example, mountains generate snow at Y=95, due to their highland climate, as their temperature value is 0.2. The temperature affects only the transition from rain to snowfall. All the biomes in vanilla with a temperature above 0.95 (and by extent, all the dry biomes) are hardcoded to never have precipitation at any height or temperature. For example, savannas do not experience rain or snow due to their heat. If a biome with a temperature above 0.95 is edited to allow precipitation through a data pack or mod, it simply behaves like a normal rainy biome.

Biomes are split into 5 categories based on their temperature: snow-covered, cold, temperate/lush, dry/warm, and neutral. They are almost always separated during terrain generation to prevent biomes with huge temperature differences being placed side-by-side (such as a snowy taiga next to a desert), and to allow biomes with similar temperatures to be placed next to each other more often (such as forests and swamps).

Generation
Minecraft biomes are generated in layer stacks. These layers generate specific aspects of Minecraft biomes, such as scale, rivers, mutated biomes, and biome categories.

Earlier stages
Biome generation is initialized as a 1 to 4096 scale of ocean, with a few spots of landmasses scattered throughout. This map is then scaled and additional landmasses shuffled around to decrease the amount of ocean, twice, to reach a scale of 1 to 1024. Additional layers that decrease the amount of ocean are repeatedly applied until the ratio of land to ocean is about 50-50. Snowy biome categories are then assigned to a few spots of land, which is then shuffled around a final time to obtain a ratio of 33% ocean and 67% landmass.

At this stage of biome generation, the final climate zones are applied as follows. Areas of warm landmasses are assigned to be a lush biome if it borders a cool or frozen landmass. Areas of snowy landmasses are assigned to the cool/temperate temperature category if it borders a lush or hot temperature zone. 1 out of every 13 landmasses is then marked as "Special", which would be used to place some of the rarer biomes in later stages of biome generation. This map is then scaled twice, until a scale of 1 to 256. An additional layer is applied to create a more jagged coastline, creating areas of large islands and lakes around the coastline. 1 out of 100 areas of Oceans are assigned as Mushroom biomes and areas of ocean far from the coast converted into Deep Ocean.

The final areas of climate areas are as follows: 31% Ocean, which consists of 22% Deep Ocean and 9% Ocean, 0.07% Mushroom, 13% Hot/Dry, 22% Lush/Warm, 23% Cool/Temperate, and 6% Frozen/Snowy. Areas of rare biomes make up 4% of the total area.

The biome generation is then split into 3 separate stacks.

Generation of Biomes and biome variants
The other stage of biome generation generates the actual biomes in-game. The biome categories generate the following biomes as follows. Some biomes are weighed more and as such generate more commonly, than other biomes. Snowy biomes have an unused rare biome variant, and as such generate as normal snowy biomes.


 * Hot/Dry Biomes: Desert (3 times), Savanna (2 times), Plains
 * Hot/Dry Biomes (rare): 1/3 Badlands Plateau, 2/3 Wooded Badlands Plateau (0.9% of the final map)
 * Lush/Warm Biomes: Forest, Dark Forest, Mountains, Plains, Birch Forest, Swampland
 * Lush/Warm Biomes (rare): Jungle (1.5% of the final map)
 * Cool/Temperate Biomes: Forest, Mountains, Taiga, Plains
 * Cool Temperate Biomes (rare): Giant Tree Taiga (1.6% of the final map)
 * Snowy/Frozen Biomes: Snowy Tundra (3 times), Snowy Taiga (1 time)

Since Village and Pillage, Bamboo Jungles overwrite certain areas of Jungle Biomes.

This map is scaled twice until a scale of 1 to 64 in both Java and Bedrock Editions. In Legacy Console Edition, the map is not scaled at all at this stage of biome generation. To ensure a smooth transition between biomes, some biomes generate an "edge biome" as follows. These edge biomes can also generate hills and modified biome variants:


 * Badlands Plateau and Wooded Badlands Plateau generate regular Badlands on all edges.
 * Giant Tree Taiga generates the regular Taiga on all edges, unless there is a pre-existing Snowy Taiga or Taiga bordering it.
 * If a Desert borders a Snowy Tundra, a Wooded Mountains can generate.
 * If a Swamp borders a Jungle, a Jungle Edge can generate. If a Swamp borders a Desert, Snowy Plains, or Snowy Tundra, a Plains biome will generate.

Modified and hill biomes are then merged into the biome generation. Most biomes have a "hills" variant but some biomes use other biomes as their "hills" variant, which are listed below. This stage also allows islands to generate in areas of Deep Ocean:


 * Dark Forest -> Plains
 * Plains -> 1/3 Wooded Hills, 2/3 Forest
 * Snowy Tundra -> Snowy Mountains
 * Ocean -> Deep Ocean
 * Savanna -> Savanna Plateau
 * Deep Ocean -> 1/2 Plains, 1/2 Forest
 * Wooded Badlands Plateau and Badlands Plateau -> Regular Badlands

Swamps and regular Badlands do not generate a hills biome variant. Oceans do not have a "modified" biome variant. While most biomes have a "modified" variant, few biomes generate a unique "modified hills" variant, such as Birch Forests and Mountain biomes. Some other biomes use another existing biome as a "modified hills" variant. If a biome does not have a "modified hills" variant, such as Swamps or Snowy Taigas, the regular biome variant generates instead.

Additional areas of Sunflower Plains are generated separately to the modified biome stage of biome generation, covering 1/57 of normal Plains biome.

The map is then scaled and the coastline made more jagged, then scaled again and beaches are generated. The generation of shorelines and beaches are as follows, this also adds a few additional biome edge biomes for Jungles and Badlands, without biome variants:


 * Beaches generate on all coastlines except the regular Swamp and regular Badlands biomes.
 * Stone Shore generates on the coastline of the regular Mountains and Wooded Mountains biomes.
 * Snowy Beaches generate on the coastline of all Snowy Tundra and Snowy Taigas, including their variants.
 * Mushroom Field Shore generates on the coastline of all Mushroom Fields biomes.
 * a regular Desert Biome generates on the edge of all Badlands biomes, excluding eroded Badlands.
 * A Jungle Edge biome generates on the edge of all Jungles biomes, unless it borders a regular Forest or regular Taiga.

This also creates unique quirks in generation, where Gravelly Mountains and Swamp Hills generate a regular Beach biome, and Swamp Hills bordering a regular Jungle Edge, with a Modified Jungle Edge bordering Jungles.

This biome map is scaled two more times (scaled 4x) until a scale of 1 to 4. River generation is merged with the regular biomes, then ocean climate zones merged.

Generation of rivers and hills
A layer stack for river noise generation is used as a random number generator to generate areas of hills and mutated biomes, which is scaled twice before applied to the biome stage of biome generation at scale 1 to 64. Since Update Aquatic, Mutated biomes conform to an entire biome or can border a river. A separate layer stack to generate rivers throughout is scaled 4 times, before it is merged with the rest of the generation at scale 1 to 4.

Rivers generate across all land biomes excluding areas of Oceans. Frozen Rivers replace rivers in regular Snowy Tundras. Mushroom Field Shore generates in place of rivers in Mushroom Fields biomes.

Once the Ocean temperature stack and river generation stack is merged with the biome generation stack, a final layer is applied to make the biome scale 1:1, which is the final biome generation used in Minecraft.

Ocean Temperature generation
This applies to Java Edition since Update Aquatic only.

Ocean biomes generate their climate zones separately from land biome generation, to avoid changing existing Minecraft seeds/biome generation in its entirely. Ocean climate zones are initialized at a scale of 1 to 256, then scaled 6 times, before it is merged with the rest of the biome generation.

In Java Edition, ocean climate areas are done so Warm Oceans cannot border Frozen Oceans. One must go incrementally from Warm Oceans, to Lukewarm Oceans, regular Oceans, and Cold Oceans, before reaching Frozen Oceans.

If a Frozen Ocean or Frozen Deep Ocean borders a land biome, a regular Cold Ocean will generate. If a Warm Ocean generates next to a land biome, a regular Lukewarm Ocean will generate. Warm Oceans overwrite Deep Oceans as Warm Deep Oceans do not generate.

Ocean climate zones are based off the 48 bit seed, unlike the rest of the land biome generation, as such, shadow seeds in Java edition contain entirely different ocean climate areas, even though common land biomes generate identically in Java Edition shadow seeds.

Other information


$$, the possible shapes of biomes can use only the first 24 bits of the 64-bit world seed, and biome shapes within a world seed can repeat beginning around blocks from 0,0. Biome generation overflows at blocks from 0,0. However, as biomes are generated in a zoomed out stage, before it is scaled upwards, it technically means that biome generation could extend further out during earlier stages of biome generation as the integer overflow point is further out.

Even though there are 64-bit seeds on Java, there are only unique noise maps for continental/ocean biome generation, due to a use of a quadratic equation in biome generation. This is colloquially known as a shadow seed. In this case, land biome and general ocean biomes are exactly the same in a pair of seeds, but ocean biome temperatures, structures, and hills differ in the shadow seed. A user can find a shadow seed by adding the constant -7379792620528906219 to their current world seed, to obtain the shadow seed. Shadow seeds are exclusive to Java Edition.

With using 32-bit seeds and a different world generation algorithm, there are few similarities between it and the 64-bit world generation. The positions of Mutated biomes, oceans (and islands), rare biomes (jungles, badlands, mushroom fields, giant tree taiga), as well as specific biomes in cold, temperate, or dry biome clusters, bear some geographical relationship with the equivalent positive value seed of the 64-bit generation. The biome shapes deviate significantly. The specific generation of lush biomes and ocean variants is completely different on Bedrock.

Biome types
$$, currently, there are 67 Overworld biomes, 5 Nether biomes, 5 End biomes, and 2 unused biomes, with a total of 79 different biomes. $$, however, there are 66 Overworld biomes, 5 Nether biomes, 1 End biome, and 3 unused biomes, with a total of 75. Biomes can be distinguished by the grass, and leaf colors (water color also differ between biomes in the biome, along with the types of blocks present (e.g. types of trees or other plants like cacti, sand coverage in deserts)). Biomes are pseudo-randomly generated using the map seed.

Biomes are separated into 6 temperature classes. The snowy ones have their temperature listed in purple, cold in green , temperate/lush in orange , dry/warm in red , and the end in blue. The biomes of either neutral or unknown temperature have no temperature class. Temperatures are given at sea level.

Snowy biomes
In these biomes, it always snows instead of rains and no matter the height; all sources of water exposed to the sky are frozen over. The foliage and grass is aqua, and the water is purple.

Cold biomes
In these biomes, it begins to snow above y=90 in mountains and stone shore, above y=120 in taiga and giant spruce taiga, and above y=150 in giant tree taiga. Otherwise, it rains. Foliage is aqua as in snowy biomes, with the water being indigo.

Temperate/lush biomes
In these verdant biomes, it begins snowing over the 256 block height limit, snow does not generate naturally. Otherwise, it rains. The foliage and grass is a vibrant light green, except for swamps and dark forests, which have dark green grass. Rivers and birch forests are also exempt from this, as they have a dull aqua hue. The water is blue in this biome.

Dry/warm biomes
In these biomes, it neither rains nor snows at all, but the sky still turns overcast during inclement weather. The foliage and grass is an olive tone, except badlands biomes, which have brown grass. The water is light blue. As in jungle biomes, the sky becomes lighter. Additionally, a snow golem spawned or brought into one of these biomes melts unless it has the Fire Resistance effect.

Ocean biomes
Oceans are large, open biomes made entirely of water going up to y=63, with underwater relief on the sea floor, such as small mountains and plains, usually including gravel. Oceans typically extend under 3,000 blocks in any direction; around 60% of the Overworld's surface is covered in ocean. Small islands with infrequent vegetation can be found in oceans. Passive mobs sometimes can spawn on these islands, as hostiles can. Squid spawn frequently in the water. Underwater cave entrances can be found frequently at the bottom of the ocean.

Unused biomes
These biomes don't generate in default worlds.

Removed biomes
These biomes no longer generate in current versions of the game.

The Nether
The Nether is considered a different dimension. All biomes in this dimension are dry and it is not possible to place water in these biomes, though ice can still be placed.

The End
The End is considered a different dimension. The water is lilac.

Trivia

 * The term biome is analogous to its scientific usage: in real life, a biome is climatically and geographically defined by distinctive communities of plants, animals and soil organisms supported by similar climatic conditions. They are often referred to as ecosystems.
 * Most biomes in the Overworld are based on real world counterparts. Mushroom Fields, Roofed Forest/Dark Forest, and Swamp biomes (and their variants) parallel real world biomes except for the addition of giant mushrooms, which don't exist in reality. Biomes in the Nether and The End obviously don't exist either.
 * It is possible for biomes to be a single block in size.
 * Winter Mode in Alpha 1.0.4 would never let the snow go away.