The time series plot show that above-average short-rains fell during much of the latter half of the 20th century. Intense rains (anomalies exceeding 1σ) were recorded around the 1960s, followed by deficits and then surpluses towards the close of last century. A continuation of the wet anomalies is implied by the models' projection of a statistically significant upward trend persisting throughout the 21st century.
From the long-rains time series plot, it is evident that an out-of-phase low-frequency pattern of variation with the second season rains is possible. For instance, the rainfall deficits which started to befall this region from the 1970s persisted longer during MAM season (extending up to the 1990s). There has been a recovery during the very last years of the 20th century, which is projected by the models to continue in the form of a steep wettening trend during most of the 21st century. Note however that the signal-to-noise ratio in the model projections for this season is comparatively low.
The apparent dryness in this area result from more grids falling within the driest northern Kenya areas. The models overestimate the observed mean monthly precipitation in this area. Almost all models project an increase in monthly rainfall during the rainy seasons, a mild exception being the HadGEM1 and HadCM3.