The time series plots for the short-rains season show that this region experienced predominantly above-average seasonal rainfall during the latter part of the 20th century. The climate models project a continuation of slightly wet conditions in this area during almost the entire 21st century, with very weak variations. This is consistent with lack of significance in mean precipitation rates and extreme precipitation changes projected in the coastal areas.
During this season, higher rainfall amounts are received than during the short-rains. In sharp contrast with the short-rains season, this area received below-average "long-rains" during much of the second half of the 20th century. Models project a reversal of the 20th century deficits from the early part of the 21st century. However, these projections are less reliable (low signal-to-noise ratio).
Wet biases in models' simulations of the 20th century annual cycle are clearly evident. Almost all the models inflate the amplitude of the annual cycle throughout the year. The model wet biases are more remarkable during the short rains. The duration of the short-rains is too long in most models. With regard to their future projections, almost all models give indications for an increase in mean monthly precipitation during both rainy seasons, as well as during the drier periods. The HadGEM1 model is the only outlier projecting drier conditions. The HadCM3 project a reduction in monthly mean precipitation only from the end of the long-rains (May) toward the beginning of the short-rains (September to November).