Like most cats, I don’t love wet fur. I check a weather app every morning to see if I need an umbrella. But how rain happens was a mystery to me.

So, I talked about rain with my friend Nathan Santo Domingo. He’s a field meteorologist with AgWeatherNet of Washington State University. That’s a weather tool for farmers, gardeners and other people in Washington.

“The first thing to remember is that Earth's surface is 71% water,” Santo Domingo said. “We also have a giant orb in the sky—the sun—that’s feeding energy into the atmosphere and reaching down to Earth's surface.”

The sun’s energy changes the water in the oceans, rivers and lakes. The water changes from a liquid to a gas called water vapor. That water vapor floats up into the bubble of gas that surrounds Earth—called the atmosphere.