The control of elevation on the spatial distribution of rainfall explains the moderate to strong correlation between
monthly rainfall data, see Table 2. Apart from the two dry months of July and August the correlation ranges
from 0.50 to 0.97. The correlation coefficients of Table 2 have been averaged as a function of the
time lag between months, excluding July and August. Fig. 3 shows that the average correlation between
rainfall measured over two consecutive months
lag 1 is 0.9 and slightly decreases to 0.8 as the separation
time increases.