Moisture-cured poly(urethane–urea) (PUU) is widely used in automotive, construction, and electronics applications because of strong adhesion, durability, and ease of use. This study provides a comprehensive evaluation of kinetics–elasticity relationships in moisture-cured PUU through correlation of thermomechanical properties with curing conditions. Consistent with the rate law, higher humidity and temperature accelerate curing kinetics and thereby alter the PUU network structure, notably the crosslink density. The curing kinetics of moisture-cured PUU were quantified by infrared spectroscopy and dynamic mechanical analysis across a range of curing conditions. These structure–property relationships then link curing conditions to thermomechanical properties in PUU.