Abstract: <p>Dengue fever, an expanding arboviral threat in tropical and subtropical regions, has resurged sharply across the Americas and the Caribbean. Guyana has recorded one of the highest reported cases in the region, yet limited research has examined the climatic determinants of local transmission. This study investigated the relationship between dengue cases, rainfall, and temperature in Guyana between 2022 and 2024. Monthly dengue case data were obtained from OpenDengue, while rainfall and temperature records were compiled from national and international sources. Descriptive statistics, Pearson correlations with one- to three-month lags, and Seasonal-Trend Decomposition using Loess (STL) were applied. Dengue incidence increased nearly fourfold over the study period, rising from 11,811 cases in 2022 to 45,080 in 2024. Correlation analysis revealed statistically significant positive associations between dengue cases and minimum, mean, and maximum temperatures across all lags (r = 0.423-0.520, p ? 0.01), with maximum temperature showing the strongest association at lag 0. Rainfall, however, exhibited weak and no significant negative correlations at all lags. Seasonal decomposition indicated recurring mid-year peaks coinciding with the May-July rainy season, and secondary surges during hotter, drier months (September-October). These findings suggest that temperature exerts a stronger and more consistent influence on dengue transmission dynamics in Guyana than rainfall, likely due to vector ecology and water-storage practices that decouple breeding from precipitation. The results emphasize the value of temperature-based early warning systems, enhanced vector control, and strengthened surveillance to mitigate dengue risk under changing climatic conditions.</p>
