Abstract: This study investigates the relative contributions of the interdecadal Pacific oscillation (IPO), Atlantic multidecadal oscillation (AMO), and global warming (GW) to the decadal variation of land precipitation in North America from 1934 to 2018. The singular value decomposition (SVD) analysis for the North American land precipitation and sea surface temperature (SST) in the middle and low latitudes reveal that the main SST modes affecting the interdecadal variation of land precipitation are the IPO and AMO, with values of 42.33% and 23.21% in winter and 21.60% and 32.66% in summer, respectively. A linear regression model is then used to analyze the relative contribution of the three signals (IPO, AMO, and GW). For North America, results show that the AMO contributes dominantly, while IPO only plays a secondary role to IPO in summer. However, the opposite behavior is observed in winter. GW is also found to play an important role. In summer, AMO is the primary contributor to the changes in precipitation in Alaska, whereas GW dominates in Canada. Meanwhile, GW, AMO, and IPO are of equal importance in the USA and Mexico. In winter, GW is the primary contributor to the changes in precipitation in Alaska and Canada, whereas IPO dominates in the USA and Mexico. In terms of information flow, this study presents the regions of sensitivity to the three modes. Results are verified using the ECHAM 4.6 model, showing that the Indian Ocean is pivotal in having the AMO and IPO in effect, causing the precipitation variabilities.