How do I change the biome of a plot?

[French_bread_gud]

Im trying to make a plot have snow as weather but I have no idea how to set the biome, so it rains instead. I know that its possible because the set weather mentions that in cold biomes it will snow.

 

[Requals]

//setbiome (if noble+)
if you arent ranked you can ask someone, however people with better ranks have more w/e blocks so it's easier to fill an entire space