Atmokinesis

To cause rain, you may wish to try the Rain Chant from the magic section.

About Atmokinesis
The ability to manipulate the weather. It operates by making subtle changes to wind, air pressure, temperature, and the earth’s electromagnetic field. These changes eventually bring out a change in the weather.

Weather Changing - Tech 1
Find something you can use to channel your energy. If you practice magic, a simple wand or athame will do. Close your eyes and visualize the kind off weather that you want to bring about. Be as specific as possible. Try to hear the wind, smell the rain, feel the change in temperature, what ever. Then, imagine sunlight ( the most influential force in weather) pouring into you. Let it build up in your solar plexus and when you're ready, release it into the sky through the tool you've chosen. It might also help if you literally tell the energy what to do as you release it.

Weather Changing - Tech 2
For this one you might first want take time to meditate. Think about what kind of weather you wish to bring about and channel the appropriate elemental energy. When you're ready, stand in the grounded position, and cup your hands together to make a ki ball. Visualize the ball's energy in the form of the element you need {wind, rain, lighting, or again, just simple sunlight.} Tell your ki ball what it needs to do and when you feel it's ready, release it and Visualize it zooming into air and exploding its energy throughout the sky.