The air masses observed most frequently over western Europe are:

The most frequently observed air masses over western Europe are polar air and tropical air. Polar air typically originates from higher latitudes and brings cooler weather conditions, while tropical air comes from lower latitudes, introducing warmer air masses. The interaction between these two types of air masses plays a significant role in the weather patterns experienced in western Europe, leading to varied and dynamic weather conditions throughout the year.

In this region, polar maritime air, influenced by the North Atlantic Ocean, is particularly prominent, contributing to mild and moist conditions. Tropical maritime air from the south also has notable impact, especially during the warmer months, leading to warmer temperatures and increased humidity.

The combination of polar and tropical air masses helps create a transitional climate that can result in a variety of weather phenomena, including rain and temperature fluctuations. Understanding these air mass characteristics is essential for interpreting weather forecasts and patterns in western Europe.