Maya Lowlands climate researchers have set aside earlier beliefs that Maya civilization flourished in an unchanging environment. Analyses of river discharge, weather patterns, lake-bottom sediments, and settlement patterns reveal a highly variable climate, considerable diversity in local geology and soils, and a wide range of cultural adaptations tailored to distinctive subregional settings. Significant knowledge gaps remain. Among the unanswered questions is how cities in the elevated interior were maintained without natural, permanent bodies of water even during equitable climatic conditions, much less through the episodes of severe drought that have become apparent in studies of past climates. The research reported in this article lays the groundwork for climate studies in the southwestern Yucatan Peninsula.