A mud sag monitoring system may be configured for real-time evaluation of sagging potential of a circulating mud. The monitoring system may include both physics-based sagging prediction models and data-driven sagging detection classifiers that allow for predicting the sagging potential. The sagging potential may also be quantified with a sagging severity index and associated with a specific location within the mud circulation system. The sagging severity and location predictions may provide a framework for mitigation of mud sagging using automatic control techniques.