Sloshing of liquids in partially filled containers generates fluctuating and transient pressures on tank walls, which can lead to structural damage, vehicle instability and containment failure. We develop flexible, non-intrusive pressure sensing systems, multimodal measurements, and data-driven analysis to characterize these dynamics and monitor the sloshing induced pressure and vibrations. This enables safer and smarter design of liquid storage or transportation systems and move toward real-time monitoring.