Climate is the average of long-term weather conditions, with a period of over 30 years. Some of the most commonly measured weather variables are temperature, humidity, atmospheric pressure, wind and precipitation. In a broader sense, climate is the state of the components of the climate system, which includes the ocean and the ice on Earth. The climate of a place is affected by its latitude, relief and altitude, as well as by the bodies of nearby bodies of water and their currents.
More often than not, the “climate” of a region is the present state of the climate system. Climates can be classified based on the average and typical ranges of different variables, most often temperature and precipitation. The most commonly used classification scheme was the Köppen climate classification. The Thornthwaite system, used since 1948, integrates evapotranspiration as well as information on temperature and precipitation and is used to study biological diversity and how climate change affects it. The focus of Bergeron's synoptic and spatial classification systems is to define the region of the air masses that originate.