The bug
Burning mobs are not extinguished by snow in snowy biomes. However, they are extinguished by snow in cold biomes where the snow starts at a certain height.
This also happens with medium biomes with the snow above y = 256.
How to reproduce
Create a Buffet world with biome "Snowy Taiga" (for example, you can choose any snowy biome)
Run
/weather rainSpawn a zombie when it's day or use
/summon zombie ~ ~ ~ {Fire:1000s}→ It won't get extinguished by the snow
Repeat the process with a "Taiga" Buffet world above y = 140
→ The zombie will get extinguished by the snow
Linked issues
discovered while testing 1
relates to 2
Comments 4
Oh I get it now. There aren't any fully rainy biomes at all, just fully snow and non-weather ones (desert, savanna, etc). Evidence here shows that every biome (includes oceans) that can rain must inherently snow as well. This can be proven by travelling above the block height limit to find snow falling in any rain type biome (Warm Ocean starts at y=280-288), even though the snow will never reach any block ever.
Basically, mobs and blocks are extinguished in "cold biomes" but not "snowy biomes" because there's no such thing as a "cold biome", it simply snows above all rain biomes.
Yes, that's the technical reason for why this issue occurs, but intuitively it doesn't make sense as to why snow should act differently in snowy and rainy biomes.
violine1101
kingbdogz
Confirmed for 18w43c.