Although Ameiva exsul is among the most common species of lizard found throughout the Puerto Rican Bank, studies examining the thermal ecology of the taxon remain scarce. In order to better understand the daily activity cycle and thermoregulatory behavior of A. exsul, daily activity and microhabitat data were analyzed along with thermal data including weather, air temperature, and relative humidity. A relative significant relationship was found between number of encounters and time of day, month, or weather. However, significantly more individuals were encountered active on the ground during the morning hours, whereas at night more were found sleeping under various substrates. Although no significant relationship between microhabitat, activity, and weather was detected, more individuals were encountered sitting under substrate during clear and cloudy/rainy conditions, whereas during partly cloudy weather lizards were more active. Significantly more individuals were encountered during warmer temperatures with less humidity. There was no significant relationship between air temperature, relative humidity, microhabitat use, and activity. However, there was a significant relationship between temperature and the number of individuals active on the ground. Future studies are needed that examine the physiological ecology of the species more closely, which include other potentially relevant environmental variables such as body temperature and wind velocity. This will provide a more comprehensive analysis on the daily activity patterns and thermal ecology of the species, which may in turn be applicable to other congeners distributed throughout similar environments.