This manuscript provides a methodology for the reconstruction of a rainfall field when there are scarce rain-gauge stations available. This situation typically arises when measurements are taken from meteorological stations across time, and the information for the complete field is required as an input for larger scale models. The proposed method is based on a wavelet reconstruction technique that requires no distributional assumptions, but relies on the relation between rainfall and normalized difference vegetation index to account for the unobserved spatial variability of the field. The methodology is applied over a region of the southern Peruvian Andes where data gathered from meteorological stations provide enough statistical significance. A comparison with respect to an alternative source of spatial variability and common practices is provided. © 2018 Informa UK Limited, trading as Taylor & Francis Group.