Climate Change Weakens Early Rains in the Caribbean: Drought Hits Puerto Rico and Jamaica

Since May 2026 Puerto Rico, Jamaica and several smaller Caribbean islands have been experiencing unusual dryness. An attribution analysis points to human-caused warming and changes in atmospheric circulation as the main drivers of the reduced early wet-season rainfall.

After a wet late winter, into drought

Following above-average rainfall in late winter and early spring, conditions in parts of the eastern Caribbean deteriorated sharply from May 2026. Puerto Rico, Jamaica, and St. Lucia, St. Vincent, the US Virgin Islands, Grenada and St. Kitts report persistent rainfall deficits and very high temperatures. River levels are falling, drinking-water reservoir storage is declining, agricultural soils are drying out, and water-use restrictions are in place in many areas.

Study: human influence amplifies drying

A recent analysis by World Weather Attribution shows that the reduction in early wet-season rainfall cannot be explained by natural variability alone. In a climate warmed by greenhouse gas emissions, the likelihood of reduced rainfall at the start of the season has increased. Natural variability remains relevant, but the warming trend is shifting the baseline conditions.

What is driving the rainfall decline

Two mechanisms act together: higher air temperatures speed up evaporation over land and sea, causing soils to dry more quickly. At the same time, large-scale circulation patterns are changing; the position and strength of seasonal low-pressure and convergence zones are shifting. As a result, the typical rainy periods of the early season more often start later or are weaker. Without sufficient rainfall, the extra heat further intensifies drying.

Local impacts

In urban areas, lower river levels and constraints on drinking-water supply are affecting industry and tourism. In agriculture, water shortages and heat stress are reducing yields of staple and export crops. Ecosystems such as wetlands and forests are under pressure: possible outcomes include species losses, reduced landscape water storage capacity and increased fire risk. For households with limited access to alternative water sources, health risks rise.

Measures with short- and medium-term effects

Short-term responses focus on water allocations, irrigation restrictions, emergency distributions of drinking water and targeted support for farms. In the medium term, improved rainfall and reservoir monitoring, flexible irrigation systems, protection of catchments and investments in storage infrastructure become increasingly important. Desalination plants can close supply gaps but are energy- and capital-intensive. Decentralized rainwater harvesting and more efficient water networks offer practical complements.

Reorienting planning

Because the decline in early wet-season rainfall is being amplified by human-caused warming, infrastructure and water-management plans must be revised. Storages designed around historical patterns will provide less security in the future. Integrated approaches with scenario analyses and dynamic risk assessments can help make supply systems more resilient.

International support and local action

Small island states often have limited resources to adapt to changing rainfall patterns. Technology transfer, financial support and technical advice can accelerate the development of resilient water systems. At the same time, local measures remain crucial: protecting catchments, adapting farming practices and social safety nets for the most affected populations.

Outlook

The study results suggest that early dry spells could become more frequent with continued global warming. How resilient communities remain will depend largely on decisions made today about water infrastructure, land use and emergency preparedness. The current drought in the Caribbean shows that climate change is not only shifting temperature records but also altering the seasonal structure of rainfall — with immediate consequences for water availability and livelihoods.