Volcanoes are a potential hazard to over 750 million people worldwide. Accessing them to install monitoring equipment can be logistically challenging and dangerous. Traditional monitoring equipment is expensive and not available to many local communities. A new, low‐cost method is proposed to address these challenges using a unique 3D thermal photogrammetric modelling workflow. The data acquisition and processing part of this workflow has been tested on Stromboli, a volcano in the Aeolian Islands of Italy. Unmanned aerial vehicles (UAVs) were deployed at the volcano to acquire both visible and thermal infrared imagery. Both datasets were then digitally processed to produce 3D virtual outcrop models. Finally, the two datasets and models were integrated to produce the first 3D thermal photogrammetric model of an active volcano. The result is an easy‐to‐use workflow applicable to any volcano. This low‐cost monitoring system could be deployed in developing countries and remote areas otherwise hindered by limited budgets and poor access.