Int. J. Environ. Res. Public Health 2011, 8 921 Figure 1. Effect of climate variability (standard deviation of precipitation) on per capita malaria cases with 95% confidence intervals. This graph is the plot of the function in Equation (8). It describes the impact of climate variability measured as the standard deviation of precipitation on malaria prevalence. Figure 2. Effect of temperature levels on per capita malaria cases conditional on climate variability with 95% confidence intervals. This graph is the plot of the temperature function in Equation (8). It shows how temperature levels affect malaria prevalence given the current climate variability conditions measured as the standard deviation in precipitation. We tested several model specifications in which; (1) an interaction term of temperature and precipitation is included in the model, (2) three interaction terms resulting from combinations of the three climatic factors are included in the model, and (3) pure linear model specifications with or