Snow sometimes doesn't occur naturally within 8 blocks of the edge

Snow sometimes doesn't occur naturally within 8 blocks of the edge.

Steps to reproduce:

Start a world with the seed 2 and go left from spawn (pic 1)
Start a world with the seed crater and go forward and right from spawn (pic 2)
Start a world with the seed 6, immediately turn around, and go left and forward (pic 3)