A long-standing problem.

Controlling the temperature system generated by Biomes does not seem to work.

Anyway create a default map will be like this.

See the picture!

(e.g  Next to the snowy field is the tropical jungle)

The map seed in the picture is "-1984077981"，XYZ: 9493 ~ 552

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The normal situation should be(From the wiki):

Biomes are split into 5 categories based on their temperature: snow-covered, cold, medium, dry/warm, and neutral. They were separated 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)