Puerto Rico has year-round mosquito activity due to its tropical climate, with peak risk during the rainy season from April through November. The metropolitan San Juan area, coastal lowlands, and areas with poor drainage carry the highest exposure. The mountainous interior has somewhat lower risk.
Dengue fever is the primary concern, with Puerto Rico being one of the most affected US territories. Chikungunya and Zika have also caused major outbreaks, particularly the 2016 Zika epidemic. The territory has well-established surveillance but cannot eliminate the tropical vector populations.
Aedes aegypti is the dominant vector in urban areas. Aedes albopictus is also established. The CDC and local health authorities conduct ongoing surveillance, but the tropical climate ensures persistent risk.
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Explore mosquito risk briefings for other destinations in Central America & Caribbean.
Disease presence data is sourced from WHO, CDC, ECDC, and OpenDengue. This is not medical advice — consult a travel health professional before your trip.