It is very difficult and unlikely to be able to control weather. Not saying its impossible but I don't see it likely.
You can do rain dances and spells to try and make it rain, the same with conjuring wind and brining the sun out. I have done some and they do work. However, weather and mother earth go hand in hand. Sometimes the weather has its own mind and dose what it wants when it wants and can be easy to unbalance. If you do something wrong or try to conjure to hard, you might cause a sever storm or something so I don't really advise it unless situations are dire like a drought, than maybe.