The coupling at the interface between tectonic plates is a key geophysical parameter to capture the frictional locking across plate boundaries, and provides a means to estimate where tectonic strain is accumulating through time. Here, we use both interferometric radar (InSAR) and GNSS data to investigate the plate coupling of the Hikurangi subduction zone beneath the North Island of New Zealand, where multiple slow slip cycles are superimposed on the long-term loading. We estimate the plate coupling across the subduction zone over different observational periods (2, 4, and 10 years) targeting different stages of the slow slip cycles. Our results highlight the importance of the observational period when interpreting coupling maps, notably highlighting the temporal dependence of plate coupling. Through our analysis of multiple geodetic datasets, we demonstrate how InSAR provides powerful constraints on the spatial resolution of plate coupling, even in a region where a dense GNSS network exists.