Costa Rica has peak mosquito activity during the rainy season from May through November, though the Caribbean coast receives rain year-round. The Limon province on the Caribbean coast, the Pacific lowlands, and the Osa Peninsula carry the highest risk. The Central Valley including San Jose has lower exposure due to altitude.
Dengue fever is the primary concern, with increasing case counts in recent years. Malaria (P. vivax) has been reduced to very low levels, mostly in the Limon province. Chikungunya and Zika have also circulated in recent years.
Aedes aegypti is the dominant urban vector. Aedes albopictus is also established. The countrys diverse microclimates mean risk varies significantly between the hot lowlands and the cooler central highlands.
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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.