Snow golems die when it snows in moutain hills

As you can see, this snowman is not taking damage because there is a block above it.

But if I break that block...

It dies ! 

I tried this in other snowy biomes and the snowman was perfectly fine, this only happens on mountain hills, probably because it rains in lower levels of the mountain and rain kills snowmen.

I remember that it also happened on 1.13.2