It's rainning in a particular area, on a moutain biome at Y=94, where it should be snowing, causing the water to not freeze.

What I expected to happen was...:

Water sources to freeze with direct contact to the sky and enough height in a cold biome.

What actually happened was...:
Divided weather within the same biome at the same altitude.

Steps to Reproduce:
1. Go to Y=94 in a mountain biome
2. Make a pool of water
3. Some of the water sources would never freeze

Location:
Seed: -6066732876819999079
X: -147
Y: 94
Z: 77

Modifications:
Optifine
Coordinates HUD data pack
Some resource packs