Climate of the European Union

The European Union is generally characterized by a temperate climate. Most of Western Europe has an oceanic climate, in the Köppen climate classification, featuring cool to warm summers and cool winters with frequent overcast skies. Southern Europe has a distinctively Mediterranean climate, which features warm to hot, dry summers and cool to mild winters and frequent sunny skies. Central-eastern Europe is classified as having a humid continental climate, which features warm to hot summers and cold winters.

Parts of the central European plains have a hybrid oceanic/continental climate. Four seasons occur in most of Europe away from the Mediterranean. The coastal lowlands of the Mediterranean Basin have more of a wet winter and dry summer season pattern, the winter season extends from October to February while the summer season is mainly noticeable in the dry months where precipitation can, in some years, become extremely scarce.

The southern region of the European Union is mostly impacted by the Mediterranean Sea. Water temperatures there are mild in winter and warm in summer and give name to the Mediterranean climate type due to the majority of precipitation falling in the cooler months. During the summer, the weather is most frequently sunny and dry, and any precipitation falls in the form of showers or thunderstorms from cumuliform clouds. The air is usually hot during the day and pleasantly warm at night. A very small area on the southeastern coast of Spain features the desert climate, making them the only places in Europe that have an arid climate.

The western parts of the European Union experiences an oceanic climate, characterized by cool summers and mild winters for their latitude. This results in a relatively narrow annual temperature range and few temperature extremes. Cloudy conditions with frequent precipitation, low hanging clouds, and regular fronts and storms are typical in these regions. Rainfall dominates for the majority of the year, while thunderstorms are infrequent due to the limited convergence of hot and cold air masses caused by rare strong daytime heating. Nevertheless, in most oceanic climate zones, or at least a part of them, there is at least one snowfall per year.

The eastern or central regions of the European Union are characterized by a humid continental climate. This climate showcases four distinct seasons with significant seasonal temperature variations. Summers are warm to hot, often accompanied by high humidity levels. Winters tend to hover just below the freezing mark but can get even colder, with some eastern areas experiencing severe cold spells. Precipitation is evenly distributed throughout the year, and humidity remains consistently elevated. Thunderstorms are the primary source of summer rainfall. During the peak of winter, snowfall is common and frequently more prevalent than rain in many areas.

The Northern countries of the European Union experiences some of the most extreme variations in daylight length on the planet, with the sun never setting for part of each summer and never rising for part of each winter north of the Arctic Circle. This phenomenon is a result of the region's high latitude and axial tilt of the Earth.

The relatively warm climate of Northern Europe, compared to other places at a similar latitude and even somewhat farther south, is primarily influenced by the combination of the Gulf Stream and the general west wind drift caused by the Earth's rotation. This climate characteristic contributes to the region's relatively mild temperatures.

Precipitation and humidity remain high year-round, with the heaviest rainfall usually occurring during the autumn months when the relative warmth of the sea compared to the land is at its greatest.