This study focuses on understanding how terrestrial water storage, or water stored in lakes, ice, soil moisture or groundwater, changes throughout the year. Seasonal water cycle changes are important for tracking extreme weather events and climate patterns. Using advanced processing techniques for gravity satellite missions, we analyzed the timing and magnitude of the seasonal water cycles around the world. We tested common assumptions, like whether the mean seasonal cycle is symmetric or invariant at long temporal scales, and we introduced a new method to improve the detail and accuracy of the seasonal water cycle data by reducing signal noise and leakage.