The Dome of Santa Maria del Fiore in Florence, a masterpiece of Renaissance engineering designed by Filippo Brunelleschi, has been the focus of one of the longest-running structural health monitoring (SHM) campaigns on a heritage masonry structure. Since the 1980s, an extensive static monitoring system has recorded displacement and temperature data across the dome. This study presents the analysis of a 10-year continuous segment (2008–2018) of the monitoring dataset. Sensors were analysed along radial, meridian, and parallel alignments to assess spatial variability, seasonal cycles, and thermal propagation. Auto- and cross-correlation functions were used to quantify phase shifts and structural-environmental interactions, revealing lag patterns consistent with thermal inertia across masonry layers. A double-harmonic least-squares model with linear drift was then applied to displacement data. The model captured annual and semi-annual periodicities and estimated long-term displacement trends, which varied depending on sensor location, crack type, and dome geometry. The results confirmed assumptions and outcomes from previous studies over earlier efforts, confirming the stability of most observed cracks, and offering a perspective on the use of traditional statistical approaches for the analysis of long-term monitoring data from historic masonry structures.