I'm not entirely sure because this is a pre 0.9 world that was made infinite with 0.11; however, I tried in a brand new world in some kind of forest (it had oak trees and I think birch trees) but I'm not quite sure what biome technically) and it did the same thing.
I have also done some experimenting with this bug. It appears to happen on all worlds regardless of when they were created and whether they are infinite or not. I'm no expert by I suspect that raining where there's snow on the ground in old worlds is probably because it's not registered as a proper "cold biome". I suspect that the snow melting is intentional to control the snow levels due to the fact that in pocket edition snow accumulates during snowfall but I created this report essentially for conformation on that. It would be unfortunate but it would also make sense.
MCPE-10724
I'm not entirely sure because this is a pre 0.9 world that was made infinite with 0.11; however, I tried in a brand new world in some kind of forest (it had oak trees and I think birch trees) but I'm not quite sure what biome technically) and it did the same thing.
Yes, unfortunately, this bug still exists in version 0.12.2.
Unfortunately this bug has not been fixed as of version 0.12.3 which was released today.
This bug has not been fixed as of 0.13.0.
This is still present in version 0.13.2
I have also done some experimenting with this bug. It appears to happen on all worlds regardless of when they were created and whether they are infinite or not. I'm no expert by I suspect that raining where there's snow on the ground in old worlds is probably because it's not registered as a proper "cold biome". I suspect that the snow melting is intentional to control the snow levels due to the fact that in pocket edition snow accumulates during snowfall but I created this report essentially for conformation on that. It would be unfortunate but it would also make sense.
As of 0.16.1 this presumed bug still exists.