Cold in-place recycling (CIR) presents environmental and technical benefits by reusing existing asphalt pavement, reducing the use of virgin aggregates, and minimizing emissions during rehabilitation. Despite these advantages, aspects such as stiffness development, spatial variability, and temperature effects remain under-implemented in routine CIR quality control. This study evaluates the evolution of the elastic modulus in the CIR layer during early curing, using light weight deflectometer (LWD) tests under real construction conditions in Québec, Canada. Elastic modulus values were backcalculated with BackCAP software and corrected to a reference temperature of 25 °C to reduce variability associated with temperature differences. Tests were carried out at multiple time intervals (0, 1, and ≈24 hours) and locations, both longitudinally and transversely. Results showed an increase in elastic modulus over time, attributed to curing effects, and revealed spatial heterogeneity—especially across the width of the lane and at specific chainages. The outer wheel path consistently displayed higher stiffness, suggesting the influence of traffic-induced compaction. The findings reinforce the importance of spatially distributed modulus measurements and thermal correction for reliable assessment of mechanical performance at early ages. Integrating LWD testing and temperature-adjusted backcalculation into CIR quality control can improve assessment consistency. It is recommended to exclude the first 150 meters of the test section to account for equipment calibration zones. The ability to quantify modulus gain within 24 h enables agencies to optimize traffic-opening schedules and adjust compaction or moisture control, improving long-term pavement durability and reducing maintenance costs. Future research should apply advanced statistical methods to enhance the reliability and generalizability of recycled pavement performance assessments.