Rain on top of hill in snow zone

I was going on top of a hill to make a distraction from my bunker in a single player map and when I made it up there, there was 4 blocks that were raining instead of snowing. the weird part was that it was on a leveled place

what I was expecting to happen was for the whole area to be snowy
what actually happened was 4 blocks were raining
im not sure how to reproduce accept take this seed -389384699 and go to the mountain on the left and do /toggledownfall