I do not know if it is just with my world but when I have a clock that does weather clear it still rains

I do not know if it is just with my world nut when I have a clock that does weather clear it still rains

What I expected to happen....
For it not to rain or snow

What actually happened was...:
that it did rain

Steps to Reproduce:
1. Minecraft version 14w08a
2.Make a clock that does /weather clear
3