Abstract New data on the pyroclastic density current (PDC) deposit temperature ( T dep ) are provided for two prominent eruptions of Mexican volcanoes of the twentieth century: the 1982 eruption of El Chichón and the 1913 eruption of Colima. In spite of similar lithofacies, magma composition and pre-eruptive conditions, the T dep of the PDCs from the 1982 (El Chichón) and 1913 (Colima) eruptions differ significantly, with intervals of T dep of 360–420 °C and 250–330 °C, respectively. These new data emphasize that a full understanding of the physical mechanisms responsible for equilibrium temperature attainment within a pyroclastic deposit has not yet been realized. The T dep measured for El Chichón PDC deposits confirm the preliminary data published elsewhere, while Colima magnetic temperatures provide different values to those published previously. Supplementary material: T dep measurements for the different sites at El Chichon volcano and Colima volcano are available at: http://www.geolsoc.org.uk/SUP18695 .