Resource availability, environmental conditions, and competition among individuals stop populations and communities from growing indefinitely. The upper limit of a community affects populations’ trajectories, including their recoveries from disturbance, and influences which life-history strategies are advantageous at different time points. Here, we use coral cover data from 1990 to 2021 across 12 degrees of latitude to quantify how this upper limit in coral communities –referred here as “asymptotic coral cover”- relates to environmental variables across different spatial scales. We find that asymptotic cover decreases with increasing mean temperature, creating a gradient from low asymptotic cover in the northern Great Barrier Reef (GBR) to high cover in the southern GBR reefs. Our results also show that asymptotic cover is positively related to water flow, creating a gradient among sites within reefs depending on their wave exposure. Light at the seabed did not have a detectable effect on asymptotic coral cover. Given these results, we expect faster increases in coral cover in sites with low temperature and high flow following a disturbance. Our findings can help improve predictions of community dynamics and identify reefs better suited for management interventions.