Temperature data loggers were deployed in 2015, 2016 and 2017 at simulated loggerhead sea turtle nests in 52 beaches scattered along the Mediterranean coast of Spain. Results demonstrated that sand temperature is currently high enough to allow the incubation of loggerhead turtles' clutches in most Spanish beaches. The data set provides with average sand temperature in simulated nests at 40 cm deep (one simulated net per beach, one beach in each sheet, each year in...