Distribution of serotinous plants in the central Namib and adjacent areas was correlated with climatic parameters (rain quantity, variability and frequency and prevailing type of precipitation) and habitat in a Binary Multiple Regression model. The desert fringe with (a) high variability of rain (60-70% of annual mean), (b) low quantities of rain (50-100 mmyr-1), and (c) prevailing precipitation type rain rather than fog, proved most conducive to serotiny. Serotinous plants were most common in habitats where run-off accumulated, such as foothills of mountains, pans and channels, and on plains. Temporal and spatial variation of water availability, as well as intense rains and run-off, both inducing seed dispersal by water, might explain the abundance of serotinous plants at the desert fringe.