Urbanization significantly alters natural ecosystems, often creating environmental challenges for wildlife. One key modification is the urban heat island effect, characterized by elevated ambient temperatures in cities compared to surrounding non-urban areas. Understanding which traits enable species to persist in or colonize urban environments is essential for developing effective conservation strategies, particularly for reptiles—organisms that rely heavily on environmental temperatures for thermoregulation. This dataset supports a study examining thermal traits and potential activity time in Sceloporus torquatus lizards inhabiting one urban and one non-urban site in central Mexico. It includes raw individual-level data on body mass (mass, g), snout–vent length (SVL, mm), field body temperature (Tb, °C), preferred temperature (Tpref, °C) measured under laboratory conditions, substrate and air temperature (Ts and Ta, respectively, °C). Data are separated by site (urban vs. non-urban) and sex (male vs. female).