What is the primary factor that classifies air masses?

The primary factor that classifies air masses is temperature. Air masses are large bodies of air that have uniform temperature and humidity characteristics. Their classification is typically based on the latitude from which they originate, which directly influences their temperature. For example, air masses sourced from tropical regions are warm, while those that originate in polar regions are cold.

Temperature plays a crucial role in determining the properties of an air mass, influencing its density, pressure, and stability. Such characteristics affect weather patterns and conditions experienced in various locations. While humidity levels, altitude, and geographical regions are certainly important in defining the specific characteristics and behaviors of air masses, they are secondary influences compared to temperature, which is the primary classification criterion.