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Precipitation is the most relevant variable in the hydrological cycle which drives continental hydrologic processes. Its spatial occurrence and behavior are complex and its daily estimation is hard in poorly gauged regions where the topography is highly irregular. Several interpolation methods are available for this purpose, but their performance is quite uncertain. This study develops a spatial interpolation method for daily precipitation that considers both spatial discontinuities and the influence of topography. The method first identifies the precipitation occurrence in each grid-cell as a function of measurements in surrounding rain gauges, and then uses daily elevation vs. precipitation linear regressions throughout the grid-cells where precipitation occurrence is identified. These regressions are classified according to the terrain orientation with respect to the prevailing wind direction. The method was evaluated using …