Lizard activity patterns are restricted by both intrinsic and extrinsic variables. The Mexican Plateau Horned Lizard (Phrynosoma orbiculare) is endemic to México and an ambush forager and viviparous species that becomes dormant during the cooler months. The objective of this study was to determine the spatiotemporal activity patterns of P. orbiculare and the environmental conditions related to its occurrence in the natural protected area Statal Park Sierra Morelos, State of Mexico, México. We conducted samplings during 2018 and 2019. We assessed temporal activity patterns with Watson's U2 test to determine differences in activity hours between age classes, sexes, and seasons, and we evaluated spatial activity patterns through a hotspot analysis. We conducted a logistic regression model by using landsat 8 bands and indices as independent variables. Differences in temporal activity patterns (activity timing) were detected between age classes and seasons (in the juvenile group) but not between sexes. Within the natural protected area, P. orbiculare aggregated in solar glades. There is an important contribution of ultrablue and blue landsat bands to P. orbiculare occurrence. Differences in activity between age classes could be related to the heat acquisition rate of smaller individuals; meanwhile, no differences between sexes suggests that the thermal optima of females are similar to male optima. Hotspot analysis and the distribution model reveal that P. orbiculare appears on the windward slope where sunrise occurs. Solar glades are important for the species occurrence and should be protected in the studied area. These data allow future monitoring studies to help prevent population declines and illegal extraction.