How does rainfall vary between Eritrea’s plateau and western plain?

Rainfall in Eritrea varies based on elevation and regional climate patterns. On the central highlands, or plateau, the mean annual rainfall typically ranges from 16 to 20 inches (400 to 500 mm). In contrast, the western plain receives less than 16 inches of annual rainfall.1

In both of these regions, the majority of precipitation occurs during the summer months, brought by a southwesterly airstream. As one moves toward the northeastern parts of the plateau, the total amount of rainfall decreases and the duration of the rainy season shortens.1