A percentage weighting (PW) method is suggested as an alternative to the Thiessen method for calculating the average areal precipitation (AAP) over a given catchment area. The basis of the method is to divide the study area into subareas by considering the rainfall percentages considered at three adjacent station locations. This method is more reliable and flexible than the Thiessen polygon procedure where the subareas remain the same independent of the recorded rainfall amounts. The application of PW method is given for various precipitation data available in the literature. In PW method higher precipitation values are attached with smaller subareas than in the case of the Thiessen method. It is observed that the PW method yields relatively smaller sum of square deviations from the actual data among the other currently available methods.