This work demonstrates lab-scale monitoring of the dynamic viscosity of bitumen with piezoelectric MEMS resonators over a period of 120 hours at an elevated temperature of 100°C in air. The aluminium nitride-based MEMS resonator is excited in a high order roof tile shaped mode to provide high quality factors while immersed in bitumen. The results demonstrate the robustness of the MEMS sensor as it is capable to perform at elevated temperatures continuous measurements for a long time even in harsh environments like bitumen.