We all pay close attention to the daily weather forecast. It lets us know whether to put on shorts or leave the house in a winter coat or with an umbrella. But how do we know what the weather is going to be like? People who observe, study, and predict weather are known as meteorologists, and they use a wide range of tools and techniques to make predictions and forecasts. Climate, on the other hand, is the average weather in an area over long periods of time. Scientists are becoming increasingly interested understanding how climate is changing and how that affects the weather.