。
It snows a lot in Hokkaido.
Literal
Hokkaido [in-では] snow [subject-が] a-lot falls.
では combines the location particle で with the contrastive topic は, framing Hokkaido as a specific location set against unstated others — 'in Hokkaido (as opposed to elsewhere), a lot of snow falls.' Hokkaido's heavy snowfall is legendary; cities like Sapporo and Asahikawa regularly receive several meters per winter, drawing skiers from around the world.