This is the second wettest area in West Africa. For the last decades of the 20th century the area experienced rainfall deficits though the pattern began to change during the very last years of the century. There is substantial evidence in support of a likelihood of more frequent wetter-than-average years in the 21st century as shown by the high degree of agreement among models in projecting an upward rainfall trend.
The 20th century annual cycle simulated by the models is close to reality although the early-season precipitation amounts are over-predicted in some models and the peak season amounts under predicted. Almost the entire set of models give an indication of more intense precipitation during the peak of the rainy season in the future climate. Some models predict lesser precipitation during March (onset) and more precipitation in November (cessation). Whereas this result could imply a shift in the rainfall season, but implicit in the apparent lack of consensus amongst models in predicting this possible change is high uncertainty.