Why does the Ionian coast receive more rain than Athens?

The Ionian coast receives significantly more rainfall than Athens primarily due to the influence of western weather patterns and the country's complex topography.

During the winter, belts of low-pressure disturbances move in from the North Atlantic Ocean, carrying warm, moist, westerly winds. These winds encounter the western coast of Greece first, resulting in substantial precipitation along the Ionian coast and the mountains situated behind it.1

In contrast, the Pindus Mountains, which serve as the backbone of mainland Greece, act as a significant barrier to these westerly weather fronts. By forcing the air to rise and release its moisture on the western slopes, the mountains create a rain shadow effect for regions to the east, including Athens. Consequently, while the Ionian coast experiences high annual precipitation—such as approximately 52 inches (1,320 mm) on Corfu—Athens receives considerably less, averaging about 16 inches (400 mm) annually.1