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We invert daily GNSS vertical position time series for terrestrial water storage (TWS) changes and characterize their spatiotemporal patterns using various geodetic and hydrological data in Sichuan which features complex climatic and geographical conditions. Our inversion strategy depends on a variational Bayesian principal component analysis (VBPCA), which recovers the equivalent water height (EWH) changes using three principal components that explain 82% of the data variance. Various data sets from GNSS, GRACE, and GLDAS indicate an increasing seasonal water variability from northeast to southwest Sichuan. The GNSS modeling results reveal significant annual EWH amplitudes (up to 300 mm), which are largely underestimated in both GRACE‐EWH (∼120 mm) and GLDAS‐EWH (∼100 mm) products. The GNSS‐EWH also shows considerable seasonal changes in the high‐altitude plateau but …