Climatology and Large-Scale Drivers of Extreme Heatwaves in the Caribbean: From 1971 to 2025

Abstract

This study examines extreme heatwaves in the Caribbean from 1971 to 2025, focusing on their climatology and large-scale drivers. We find statistically significant increase in heatwave events, with major urban centers experiencing up to three additional heatwave days and 1°F (∼0.6°C) rise in temperatures per decade. Extreme heatwaves, where both daily maximum and minimum heat indices exceed the 95th percentile, are now more frequent, prolonged, and intense, with events reaching maximum “feel-like” temperatures above 115°F (∼46°C). These increases may be attributed to global warming, as reflected in sea surface temperatures. Strong El Niño phases raise heatwave temperatures by about 4.6°F (∼2.5°C) and increase events by about 2.15 per heat season, across the Caribbean. Diabatic heating drives 70%–80% of heatwave temperature anomalies, with adiabatic warming contributing ∼30%, and small contributions from advection. These findings enhance understanding of Caribbean heatwaves, offering insights for managing future related risks.