Are there mosquitoes in the Algarve? By day on the terrace, at dusk by the lagoon.

Yes, and they work in two shifts. The Asian tiger mosquito bites by day on terraces and in villa and golf-resort gardens, and salt-marsh and house mosquitoes come off the coastal lagoons at dusk. The disease picture is calm. No locally acquired dengue, chikungunya or Zika has ever been reported on mainland Portugal, and the Algarve's last human West Nile case was in 2015.

The tiger mosquito, here since 2017–18

The Algarve was one of the tiger mosquito's first two footholds in Portugal. It has been in the region since 2017–18, first in Loulé municipality, and Portugal's national health institute, INSA, lists samples from Almancil and Quarteira in 2018, Olhão in 2022 and Faro in 2023. By 2025 it had been recorded in Faro, Lagos, Portimão, Albufeira and Tavira. INSA notes that adults are present all year here, at lower levels in winter. In October 2022, Faro's Gambelas neighborhood hosted Portugal's first sterile-male trial, with 84,000 sterile tiger mosquitoes released over about 124 acres (50 ha).

It bites in daylight, with peaks in the morning and late afternoon, and it waits in shade and around plants, so the bites tend to come on the terrace, in the villa garden and around golf-resort landscaping. Open sand gives it little cover. Put repellent on over sunscreen in the morning and again in the late afternoon, and empty plant saucers and buckets at a villa, since it breeds in small pools of standing water. Our daytime mosquito routine has the full schedule.

Dusk on the Ria Formosa

The evening biters come from the lagoons. A 2007 survey of seven Algarve coastal lagoons, including Lagoa dos Salgados and Quinta das Salinas, found mostly house mosquitoes (Culex pipiens, 52% of adults), followed by Culex theileri (29%) and the salt-marsh mosquito Ochlerotatus caspius (11%), with adult numbers peaking in July. On the Ria Formosa the wind matters more than the calendar, and a still evening after a hot day is the worst case. Tavira, Cabanas and the eastern lagoon have the strongest reputation for dusk bites.

Near the lagoon, the salt pans or Salgados, put repellent on before dusk and wear long, light clothes for sunset dinners in Tavira, Cabanas or Olhão. Close the windows at dusk or run a plug-in vaporizer if your room has no screens. Spring and fall bring fewer bites on both shifts, though the tiger mosquito never fully leaves.

Quiet since 2015

West Nile has a history here. In summer 2004 the virus was found in mosquitoes near where two linked human cases were probably infected, in the region's coastal wetlands. In early September 2015 the Algarve notified Portugal's first reported case of West Nile neuroinvasive disease, and outbreaks in horses followed in the Alentejo and the Algarve in 2015 and 2016. Portugal had no human cases in 2025 or 2026, and 2026's four horse outbreaks were farther north, in the Setúbal peninsula, the Lezíria do Tejo and the Alto Alentejo.

CDC's Portugal page lists no malaria medicine, and the yellow fever vaccine is neither recommended nor required. It lists leishmaniasis, spread by sand flies that bite from dusk to dawn, which your dusk repellent covers. If you're bringing a dog, see a vet about sand-fly protection before the trip.

Where you're staying

Here is how the coast compares for a June–September trip.

The Portugal briefing covers the rest of the country, and our Lisbon briefing covers the capital and Sintra. Crossing into Spain? Our Seville briefing covers the West Nile season there.

What travelers report

Paraphrased from an old TripAdvisor thread and an early hotel review, both about Tavira, and linked so you can read them in full. Neither is dated, and on the Ria Formosa the wind changes things from one evening to the next.

• Tavira · dusk

  A local resident said mosquito numbers depend on when the wind blows them in from the Ria Formosa, so there are either none or millions. Others said Tavira is better than Cabanas but there are plenty around; one visitor saw almost none in two weeks and was bitten mainly near the river at dusk. The thread is about 16 years old. TripAdvisor ↗

• Vila Galé Albacora, near Tavira

  In an old review titled 'Hotel with a Buzz', the guest called the mosquitoes a menace and said the hotel supplies repellent free of charge. TripAdvisor ↗

One rule outlasts the trip. Any fever during or after your trip means a doctor visit, and you tell the doctor you were in the Algarve.

Traveler questions