Why does rainfall in Morocco decrease from north to south?

Rainfall in Morocco decreases from north to south primarily because the country is situated on the southern margins of the mid-latitude tract of frontal storm systems that traverse the North Atlantic. As these systems move, the northern regions receive more consistent moisture, while the southern areas are increasingly distanced from these primary storm tracks.1

Several additional factors contribute to this pattern:

• High-Pressure Ridges: During the rainy season, high-pressure ridges often develop offshore, which can shift storm paths further to the north and lead to drought conditions when they persist.1
• Atmospheric Stability: The cold Canary Current flowing off the western coast induces atmospheric stability, which further suppresses the potential for precipitation as one moves southward.1
• Air Mass Interaction: The region is a meeting point for humid, cold polar air masses from the north and hot, dry tropical air masses from the south, with the latter becoming more dominant in the southern latitudes.2

While this general north-to-south trend exists, elevation significantly modifies local precipitation, with mountainous areas receiving substantially more rainfall than the surrounding lowlands.13