In a rainy day in Boston, have you ever wished you had sunny weather all the time? Indeed, California has its nick name, "Sunny California." Why is the weather in New England and California so different? Starting with some understanding on ideal gas, centrifugal force, and basic thermodynamic knowledge, we will discuss the scientific reasoning for the differing weather between the two areas. The course objective is to provide the students some sense in how different parts of science are merged together to understand natural phenomena of weather.