I think the weather and biomes are messed up or out of sync. I'm getting snow falling in biomes with no snow on the ground in large area's, still get rain but it's also overlapping biomes. I did create my world back in the Alpha days, maybe thats causing the issue. Hopefully someone will make a mod to adjust weather/biomes or Notch will fix the weather aligning with biomes better. Here's a good example of the rain overlapping into the snow biome on the right. But I also get massive area's snow where there was nothing on the ground.
Do we have to start a new world in order to have weather biomes working? Nobody has noticed any new weather in the world we were using with 1.4.
Just wanted to say I have the same problem. And I'm sure it has something to do with biomes that miraculously shifted because when I place leaves (MC 1.7) in what appears to be a taiga biome, the leave gets the texture of some forest/tropical biome leave instead of a taiga texture. It also rains instead of snow. Has anyone figured out yet how to fix this? EDIT: And my world wasn't generated back in alpha