Why Morocco has become hotter and drier since 1980

Morocco’s climate is shifting toward hotter and drier conditions, with more frequent heatwaves and declining rainfall potential. This is the main conclusion of the study «Changes in Regional Circulation Weather Type in Morocco During the Period 1980–2019» , which analyzes atmospheric patterns over nearly four decades.

Published on April 28, the research shows that the country is experiencing a structural change in its atmospheric dynamics. Circulation patterns linked to heat, particularly those associated with the strengthening and northward expansion of the Saharan thermal low, are becoming more frequent. At the same time, weather systems responsible for bringing rain, especially upper-level troughs, are declining, particularly during the wet season. This dual trend is reducing rainfall while intensifying summer heat.

To reach these conclusions, the study examines daily weather patterns between 1980 and 2019, focusing on sea-level pressure and upper-atmosphere conditions. It applies statistical classification methods, notably principal component analysis (PCA) and clustering, to identify and track dominant circulation types over time.

The study also highlights important limits in previous research, which often focused on large-scale climate indicators such as the North Atlantic Oscillation or on isolated regions and seasons. By contrast, this analysis provides a comprehensive, region-wide view of atmospheric circulation directly over Morocco, helping to explain long-term climate trends rather than isolated events.