Are there mosquitoes in Uruguay? Yes, and dengue comes late in the summer.

Yes, though on a December–February beach trip they're mostly a nuisance after rain. The CDC lists no dengue, Zika or malaria for Uruguay. The dengue mosquito, Aedes aegypti, has settled in Montevideo, though, and when local dengue happens it comes late in the southern summer and into the fall, after the high season on the Atlantic coast.

Dengue is new to Uruguay, and it peaks late

Uruguay's first locally acquired dengue case was a Montevideo woman with no travel history who fell ill in February 2016, the World Health Organization reported, and Montevideo had most of that outbreak's cases. The largest outbreak on record came in 2024. The first local case was confirmed on March 1, and the Ministry of Public Health's season summary, as reported in the Uruguayan press, counted 712 locally acquired cases, concentrated in Salto and Paysandú on the Uruguay River, with local cases peaking in early April. Uruguay also had its first local chikungunya in 2023, starting with an outbreak in Paysandú that April and followed by cases in Montevideo, the press reported, citing the ministry.

Since the 2024 outbreak it has been quiet. The Pan American Health Organization reported a small number of confirmed dengue cases in 2025, with no severe cases or deaths, and none in 2026 as of its February 18 update. Its October 2026 update on dengue and chikungunya in the Americas doesn't name Uruguay. Many of Uruguay's cases are picked up abroad, mostly in Brazil and Argentina, so if your trip combines countries, follow the advice for each. Our Brazil and Argentina briefings cover them.

The ministry says the dengue mosquito is most active in March and April. For Montevideo, Salto or Paysandú from March to May, wear repellent in the daytime as well as the evening, and check local news for cases before you go. Aedes bites by day, with peaks after sunrise and in the late afternoon. Our dengue & Zika routine has the full schedule.

Summer rain and the floodwater mosquito

The mosquitoes you're likeliest to notice in summer are a different species. Almost every year from December to May, the health ministry says, rain after a dry spell sets off what it calls mosquito invasions, when the floodwater mosquito Aedes (or Ochlerotatus) albifasciatus and Culex hatch in large numbers. The ministry describes the floodwater mosquito as an aggressive daytime biter, concentrated in parks and green areas near homes. Culex bites at night. A swarm can last a few days after the rain.

In dry weather the beach resorts tend to be light on bites. After a downpour, put repellent on for daytime walks in parks and gardens as well as for the evening, and choose a room with screens or air conditioning, especially in rustic lodging on the Rocha coast. On an estancia or farm stay, note that the CDC's Uruguay page also lists Chagas disease, spread by triatomine bugs, and New World screwworm, a fly that lays its eggs in wounds. The CDC's advice is to keep wounds clean and covered, sleep in a screened room or under a bed net and limit time around livestock. Check for ticks after time outdoors, too.

Where you're going

Here is how the main stops compare for a December–April trip.

What travelers report

Paraphrased from a forum thread and linked so you can read it in full. It dates from the 2024 outbreak, and one thread can't speak for every summer.

• Montevideo · 2024 dengue season · 2024

  A thread about dengue cited news reports that the MSP called it the worst dengue outbreak in the country's history. A reply noted that mosquitoes were invading Montevideo but that these were not the kind that carries dengue. TripAdvisor ↗

One rule outlasts the trip. Any fever during or after your trip means a doctor visit, and you tell them you were in Uruguay, including whether Brazil or Argentina was on the route.

Traveler questions