The influence of subpolar North Atlantic hydrographic conditions on the North Sea is well recognized, yet the precise pathways taken by Atlantic Water to reach its gateway remain uncertain. Using satellite-derived velocity fields, we map the open-ocean routes leading to the North Sea. Our Lagrangian analysis shows that the Rockall Trough serves as the primary route in a time-mean sense, with its dominance becoming particularly evident under anomalously cold subpolar conditions. During anomalously warm periods, however, Atlantic Water is preferentially routed through the Iceland Basin. Empirical orthogonal function analysis of the Lagrangian trajectories reveals a dipole mode of variability between the Rockall Trough and the Iceland Basin, with its first principal component explaining 74% (R = 0.86) of the variance in multi-year ocean heat content variability. These trajectories further demonstrate that this variability is closely linked to the north-south shifts of the North Atlantic Current. Such spatial shifts are likely driven by variations in northward ocean heat transport at the intergyre boundary, with the strength of the subpolar overturning circulation in preceding years potentially playing a critical role. This connection suggests that the conditions in the North Sea as well as the pathways Atlantic Water is advected along to reach it could be predictable several years in advance.