Mosquitoes in Rio de Janeiro: Yellow Fever Vaccine, Dengue & Carnival (2026)

The CDC recommends yellow fever vaccine for travelers going to Rio de Janeiro state, the city and its islands included. Dengue and chikungunya are endemic and spread by a day-biting mosquito, and Brazil's health ministry has warned that El Niño could make 2027 a big season, with Carnival near its start.

Yes, though the beachfront districts have a reputation for few of them. Dengue and chikungunya are endemic in Rio, both carried by a mosquito that bites in daylight, and the CDC recommends yellow fever vaccine for travelers going to the city and the rest of Rio de Janeiro state. It reports no malaria in the city.

Disease risk ModerateEndemic dengue and chikungunya, with Rio state's last big dengue year in 2024; CDC recommends yellow fever vaccine for the city and reports no malaria there.

Bite nuisance OccasionalThe beachfront districts have a reputation for few mosquitoes; the forested hills of Tijuca and Santa Teresa bite more.

CirculatingDengueChikungunyaOropouche (Rio state, 2025)No malaria in the city (CDC)Yellow fever vaccine not required for entry

CDC noticesNo country-specific notice for mosquito-borne disease

Travel clinicCDC recommends yellow fever vaccine for travelers 9 months and older going to Rio de Janeiro state, including the city of Rio de Janeiro and all coastal islands, and no malaria medicine for the city or the state's rare-case rural areas. See a travel clinic 4–6 weeks before departure.

When to goBest: June to September, the southern winter and the low point for dengue. Worst: about February to May, when dengue and chikungunya peak in the southeast. Carnival falls in February in 2027, early in that stretch.

Data checkedOctober 2026 · sources

Yellow fever covers the city

What CDC says: yellow fever vaccine "is recommended for travelers ≥9 months old going to the states of" a list that includes "Rio de Janeiro (including the city of Rio de Janeiro and all coastal islands)." Under entry requirements: "Vaccine is not required." For malaria, it reports no transmission in the city and lists Rio de Janeiro among the states with "Rare cases and sporadic foci of transmission in rural and forested areas," where it advises "No chemoprophylaxis recommended (insect bite precautions and mosquito avoidance only)." What we suggest you do with this: book a travel-medicine appointment 4–6 weeks before departure and bring the rest of your Brazil route.

Brazil's 2025 yellow fever outbreak, 120 cases and 48 deaths by PAHO's count, was in São Paulo, Minas Gerais, Pará and Tocantins, with no cases in Rio de Janeiro state.

Dengue after the 2024 record

Rio's last big dengue year was 2024. By the end of June that year, Brazil's health ministry counted 279,062 probable cases in Rio de Janeiro state, more than eight times the 32,478 of 2023, with 195 confirmed deaths. This year has been quiet nationally, with about 470,500 probable cases through September 26, roughly 70% fewer than in the same period of 2025. No 2026 figures for the city or the state were available.

Rio de Janeiro state also had 2,497 confirmed Oropouche cases and 4 deaths in 2025, second only to Espírito Santo, according to PAHO. Oropouche spreads mainly through a tiny biting midge. Pregnant travelers should discuss Zika and Oropouche with a healthcare provider.

Wolbachia worked better in Niterói than in Rio

The World Mosquito Program has released Wolbachia-carrying mosquitoes on both sides of Guanabara Bay, with very different results. In Niterói, citywide releases were associated with 69% lower dengue incidence than in control areas. In Rio, about 67 million mosquitoes released from 2017 to 2019 reached only about a third of the wild population. After the city's Aedes population crashed in May 2022, the share carrying Wolbachia across 12 sampled neighborhoods in the north of the city averaged under 10% by November 2024, according to a review in Memórias do Instituto Oswaldo Cruz published in October 2026. That's too low to count on.

When to go, and Carnival

June to September, the southern winter, is the low point for dengue. Summer, December to March, is hot and wet, and dengue and chikungunya in the southeast peak from about February to May. Carnival falls in February in 2027, early in that stretch. In July 2026, Brazil's health ministry warned that El Niño could bring a large 2027 season, citing a Fiocruz model that projects about 1.7 million suspected cases nationwide.

The dengue mosquito bites in daylight, so put repellent on over sunscreen in the morning and again in the late afternoon. At street parties and the Sambadrome, sweat means reapplying every few hours, and our repellent timing guide has the numbers. Keep hotel windows closed with the air conditioning on, and check the bathroom for mosquitoes when you get back to the room.

Where you're going

beach

Copacabana, Ipanema & Leblon

Disease risk ModerateBite nuisance Occasional

The beachfront districts have a reputation for few mosquitoes, though the day-biting dengue mosquito still turns up. Wear repellent from breakfast and keep windows shut with the air conditioning on.

jungle

Tijuca Forest & Santa Teresa

Disease risk ModerateBite nuisance Noticeable

The forested hills inside the city are where mosquitoes are more likely. Wear long sleeves and fresh repellent for Tijuca trails and Santa Teresa's leafy streets.

city

Niterói

Disease risk ModerateBite nuisance Occasional

Across Guanabara Bay, where citywide Wolbachia releases were associated with 69% lower dengue incidence than in control areas. Dengue still occurs, so the daytime habit stays.

island

Ilha Grande & Paraty

Disease risk ModerateBite nuisance Noticeable

CDC's yellow fever advice covers all of the state's coastal islands, and it lists rare malaria in rural and forested areas with bite precautions only. Tiny black flies called borrachudos have a reputation at beaches and waterfalls.

Adding the falls? Our Iguazú Falls briefing covers both sides, and the Brazil briefing covers the Amazon and the Pantanal.

The Rio kit

The spray covers a beach week. Add the backup for Carnival.

Picaridin 20% travel sprays: odorless in the heat, layers over sunscreen and fits a beach bag.
A full-size backup in the checked bag for Carnival week, when sweat and long days mean reapplying every few hours.

Carry-on trio → 8 oz backup → Full rankings

What travelers report

Paraphrased from TripAdvisor threads and linked so you can read them in full. None gives a year, and bites in Rio vary a lot with the neighborhood and the building.

Copacabana, Ipanema, Leblon and the center
Answering an older question about mosquitoes, a forum expert said visitors won't find many or any mosquitoes in Copacabana, Ipanema, Leblon or the city center, but will near green areas such as the Tijuca forest. TripAdvisor ↗
Rio de Janeiro hotels · Easter
For an Easter trip, posters said mosquito levels vary literally building to building and suggested keeping windows closed with the air conditioning on. TripAdvisor ↗
Rio de Janeiro (city)
In a thread on mosquitoes and yellow fever, a reply said the risk for travelers staying only in the city is low but still recommended repellent. CDC nonetheless recommends the vaccine for the city. TripAdvisor ↗

One rule outlasts the trip. Any fever or joint pain during or after your trip means a doctor visit, and you tell them you were in Rio de Janeiro. If you were bitten, bitten in a dengue zone covers what to watch for.

Traveler questions

Do I need a yellow fever vaccine for Rio de Janeiro?

Brazil does not require it for entry. As health advice, the CDC recommends it for travelers 9 months and older going to Rio de Janeiro state, including the city and all coastal islands. Brazil's 2025 outbreak was in São Paulo, Minas Gerais, Pará and Tocantins, with no cases in Rio de Janeiro state, and the recommendation covers the city all the same. Whether the vaccine fits your trip is a decision for a travel clinic, 4–6 weeks before departure.

Is there dengue in Rio right now?

Dengue is endemic in Rio, but no 2026 figures for the city or state were available. Nationally, Brazil's health ministry counted about 70% fewer probable cases through late September than in the same period of 2025. The last big year was 2024, when Rio de Janeiro state had 279,062 probable cases by the end of June. The ministry has warned that El Niño could bring a large 2027 season, so check the latest numbers before a Carnival trip.

Are there mosquitoes on Copacabana and Ipanema?

Fewer than in the greener parts of the city. The beachfront districts have a reputation for few mosquitoes, and the forested hills of Tijuca and Santa Teresa for more. The dengue mosquito bites by day, so repellent over sunscreen in the morning still matters, and closed windows with the air conditioning on keep mosquitoes out of the room.

Does Rio's Wolbachia program protect visitors?

Not enough to rely on in Rio itself. Across the bay in Niterói, citywide releases of Wolbachia-carrying mosquitoes were associated with 69% lower dengue incidence than in control areas. In Rio the releases reached only about a third of the wild population, and in November 2024 the share carrying Wolbachia averaged under 10% across 12 sampled neighborhoods in the north of the city, according to a review published in October 2026. Wear repellent either way.

Sources

Health authorities, surveillance reports and news coverage of official bulletins used for this briefing, last checked October 2026. Traveler reports are linked where they appear. This page summarizes public-health guidance and is not medical advice.

Rio's beachfront has a reputation for few bites. CDC's yellow fever advice covers the whole city.