High-resolution climate data reveals how temperature and rainfall patterns are reshaping dengue transmission
As climate change intensifies weather variations across the tropics, a new study offers important insights into how shifting temperature and precipitation patterns influence dengue risk in Costa Rica—and provides a practical framework for predicting disease outbreaks at the district level.
Researchers conducted a comprehensive analysis of the relationship between climate factors and dengue incidence across Costa Rica's districts, combining high-resolution climate data with epidemiological records spanning three decades. Their findings reveal a complex interplay between seasonal weather patterns and dengue transmission that varies significantly by region and time of year.
Seasonal Climate Triggers
The study uncovered a notable seasonal pattern: temperature emerges as the dominant driver of dengue cases during the dry season (November to June), while precipitation becomes the critical factor during the rainy season (July to October). This discovery suggests that disease prevention strategies must be tailored to seasonal climate conditions rather than applied uniformly year-round.
The study reveals that temperature and rainfall follow distinct lagged patterns that can serve as early indicators for dengue outbreaks. These seasonal dynamics provide a foundation for anticipatory public health measures.
Projecting Tomorrow's Threat
Using advanced quasi-optimal regression models, the team projected dengue case numbers under future climate scenarios. Under the high-emission SSP5-8.5 scenario, certain districts could see dengue cases rise by approximately 42 cases compared to historical baselines (1985–2015) by mid-century (2035–2065). While this represents a notable increase district-by-district, the cumulative burden across regions could strain public health systems already managing dengue transmission.
From Data to Action
The district-level approach represents a significant advance over national or regional analyses. By identifying specific climate indices that drive local dengue transmission, this work enables health authorities to develop geographically targeted interventions and resource allocation strategies.
Rather than presenting worst-case projections, the study offers a practical framework for public health planning. By identifying climate-dengue relationships at the district level, public health officials can use these findings to anticipate demand on diagnostic facilities, prepare vector control campaigns, and mobilize healthcare resources ahead of peak transmission seasons.
Why It Matters
Dengue affects approximately 400 million people annually worldwide, yet predicting transmission remains challenging due to the complexity of climate-disease interactions. Costa Rica, with its tropical climate and strong epidemiological records, serves as an ideal case study for understanding how climate change will reshape dengue risk across the Americas.
The findings underscore a critical message for policymakers: dengue prevention in a warming world requires locally informed, seasonally adaptive strategies grounded in robust climate science. As global temperatures continue to rise, district-level climate–dengue assessments like this one become essential tools for protecting public health.
Science in One Health
News article
High-resolution climate–dengue modeling and mid-century projections under SSP5-8.5 in Costa Rica
22-May-2026