Marginal environments, such as urban reefs found in the Port of Miami, are hypothesized to be a source of potentially resilient reef-building corals. To determine whether urban corals from the Port of Miami were more resilient to predicted end-of-century climate conditions than their offshore counterparts, we conducted an ex situ OA and thermal stress factorial experiment with clonal cores of the scleractinian species Orbicella faveolata and Siderastrea siderea collected from two urban and two offshore sites. Following a one-month exposure to control (pH 8.05) and low (pH 7.80) pH treatments, corals were then subjected to thermal stress assays (22.5 C and 33.0 C) according to a factorial design with pH treatments. This repository contains raw sequence files associated with this experiment, prepared using the Tag-Seq pipeline.