It doesn't snow on high extreme hils/taiga

On the java edition, if you can't find a snowy biome, you can build up in extreme hills/taiga biomes to get snow and freeze water to get ice. The wiki says: "Snowfall also occurs above certain heights, thus creating "snow caps" on the top of the mountains."
However, this doesn't happen on pocket edition.

How to reproduce:
1. Find an extreme hills/taiga biome;
2. Fly up to ~256 blocks;
3. Set the time to rain;
4. It will be raining instead of snowing