What term describes the sum of all weather conditions in a specific area over time?

The term that describes the sum of all weather conditions in a specific area over time is climate. Climate refers to the long-term average of weather patterns, including factors such as temperature, humidity, precipitation, and wind, typically observed over a period of 30 years or more. This distinguishable characteristic of climate sets it apart from short-term weather, which can change from day to day or even hour to hour.

In contrast, the other terms refer to different concepts. Weather pertains to the short-term atmospheric conditions in a specific time frame, often fluctuating rapidly. The atmosphere is the layer of gases surrounding the Earth, playing a crucial role in weather and climate but not specifically defining the sum of those conditions. Forecast refers to predictions made about future weather conditions based on current atmospheric data and trends, rather than a summary of historical weather data over time.