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NoBites Abroad · Destinations · Costa Rica · Guanacaste & Tamarindo
Quick Briefing · LIR

Are there mosquitoes in Guanacaste? Few in winter, and one virus to plan around.

Disease risk ElevatedBites Noticeable
  • CDC Level 2 Chikungunya in northwest Costa Rica, Guanacaste included
  • CDC Level 1 Global dengue (Costa Rica listed)
  • Travel clinic CDC recommends medicine or vaccines for some areas · which ones
Rated for Dec–Apr tripsFull picture ↓

The CDC has a Level 2 chikungunya notice for northwest Costa Rica, and the 2026 outbreak began at Playa Langosta, next to Tamarindo, before moving north toward the Nicaraguan border. December to April is the dry season, when mosquitoes are few, and the itch on your ankles usually comes from beach no-see-ums.

By NoBites Abroad·Updated October 2026·4 min read

Few in the dry season. From January to early April residents report very few mosquitoes on the Pacific coast, and the itchy welts on your ankles usually come from beach no-see-ums. Chikungunya is what to plan around. A local outbreak began at Playa Langosta, next to Tamarindo, in July 2026, and the CDC has a Level 2 travel notice for the northwest, Guanacaste included.

Disease risk ElevatedAn active CDC Level 2 chikungunya notice covers Guanacaste, which had 404 of Costa Rica's 539 lab-confirmed 2026 cases by mid-September, and dengue is running above 2025.
Bite nuisance NoticeableFew mosquitoes from January to early April; beach no-see-ums at dawn, dusk and in still air are the steady complaint.
CirculatingChikungunya (2026 outbreak)Dengue (above 2025)No-see-ums on the beachNo CDC malaria-pill advice for GuanacasteNo yellow fever vaccine advised
CDC noticesLevel 2 · Chikungunya in northwest Costa Rica, Guanacaste included · CDCLevel 1 · Global dengue (Costa Rica listed) · CDC
Travel clinicCDC recommends chikungunya vaccination for travelers visiting an area with a chikungunya outbreak, and its current notice includes Guanacaste. It lists malaria medicine for Alajuela and Limón provinces, not Guanacaste.
Dec–Apr tripsDry season and the quietest months for mosquitoes, with very few reported from January to early April. The chikungunya outbreak was still active in September, so check whether the CDC notice is still up the week before you fly.
Data checkedOctober 2026 · sources

Chikungunya: from Tamarindo to the border

On July 1, 2026, Costa Rica's health ministry identified a local chikungunya outbreak at Playa Langosta, in Santa Cruz canton next to Tamarindo. The investigation found cases in Huacas, Tamarindo, Sardinal, Belén and Flamingo, and crews fumigated about 5,000 homes, according to press reports. By mid-September the Pan American Health Organization counted 539 lab-confirmed cases in Costa Rica for 2026, 404 of them in Guanacaste, against 8 suspected cases in all of 2025. By then the outbreak had moved north. Press coverage of the ministry's mid-September bulletin put the hotspot in La Cruz canton, on the Nicaraguan border.

The CDC's notice, last reviewed July 30, 2026, covers Alajuela, Heredia and Guanacaste plus parts of Puntarenas and San José. The CDC says "Chikungunya vaccination is recommended for people traveling to an area with a chikungunya outbreak," and it advises pregnant travelers to reconsider travel to the affected areas, particularly close to delivery.

What we suggest you do with this: ask a travel clinic about the chikungunya vaccine 4–6 weeks before departure, and bring your dates and full route. If the trip continues to Arenal or the Caribbean coast, raise malaria there too; the CDC lists prevention medicine for Alajuela and Limón, not Guanacaste. Check whether the notice is still active the week before you fly.

Chikungunya spreads through the same day-biting Aedes mosquito as dengue, and Costa Rica's dengue count, which rose sharply from May, is running above 2025. The Chorotega region, which covers Guanacaste, led the country in dengue through May, and by mid-September La Cruz had one of the highest canton rates. Repellent goes on over sunscreen in the morning, again after surfing or swimming, and in the late afternoon. Our dengue & Zika routine has the full schedule.

Beach no-see-ums at dawn and dusk

On the beaches, the steady complaint is biting midges, called sand flies or sand fleas locally and no-see-ums in the US. They leave itchy welts on ankles and calves that can show up a day or two later, and they come out at dawn, at dusk and in still air. Mosquitoes are mostly a rainy-season problem here, though homes near riverbeds and estuaries keep some through the dry months. The Tamarindo estuary and the mangroves behind Playa Grande are likely spots.

Spend the breezy middle of the day on the sand, spray feet, ankles and calves before a sunset walk, and wear light trousers for beach-level dinners. Pick a room with air-conditioning or screens. Our Barbados sand fly guide explains how midges behave.

Where you're going

Scores are for a December–April trip.

beach

Tamarindo & Playa Langosta

Disease risk ElevatedBite nuisance Noticeable

Where the local chikungunya outbreak was identified on July 1, 2026. Dawn and dusk no-see-ums on the beach are the usual winter bite; mosquitoes mostly come with the rains.

beach

Flamingo, Potrero & Conchal

Disease risk ElevatedBite nuisance Noticeable

Also in Santa Cruz canton, and chikungunya cases turned up in Flamingo during the July investigation. Expect beach midges at dusk, as elsewhere on the coast.

resort

Playas del Coco & the Papagayo Peninsula

Disease risk ElevatedBite nuisance Occasional

Sardinal, the district around Coco, was among the places with outbreak cases. Bites tend to be occasional; keep the daytime repellent habit for chikungunya and dengue.

beach

La Cruz & Bahía Salinas

Disease risk ElevatedBite nuisance Noticeable

The outbreak's hotspot by September, on the Nicaraguan border, with one of the country's highest dengue rates by canton. Kitesurf winds tend to keep midges down by day; be strict with repellent here.

Our Costa Rica briefing covers Arenal, Monteverde, Manuel Antonio and the Caribbean coast. Crossing the border from La Cruz? The Nicaragua briefing covers its countrywide chikungunya notice.

The Guanacaste kit

The spray covers daytime mosquitoes and the beach midges. The second is the plant-based alternative.
  • Picaridin 20% travel sprays: odorless in the heat, layers over sunscreen and goes on ankles as easily as arms. One 3.4 oz bottle covers about a week of daily use for one person. Reapply after every surf session.
  • Oil of lemon eucalyptus 30%: the plant-based option among EPA-registered repellents. Not for children under 3.
Carry-on trio → Lemon eucalyptus → Full rankings

What travelers report

Paraphrased from TripAdvisor threads and reviews and linked so you can read them in full. Only one is dated, from a July visit, and the dry season is usually much lighter on mosquitoes.

  • Hotel Pasatiempo (Tamarindo) · July · 2023

    A July 2023 reviewer said the whole property had a mosquito problem, worst in the room and on the patio. The pool area also had lots of mosquitoes, which made it hard to enjoy with young children. TripAdvisor ↗

  • Tamarindo

    One visitor said no-see-ums bit her husband heavily while she was rarely bitten. Another poster had no bug trouble at all and put it down to the wind. TripAdvisor ↗

  • Guanacaste beaches

    A visitor got dozens of itchy bites on the calves and ankles from beach biters. The bites showed up a couple of days after the beach visit. TripAdvisor ↗

One rule outlasts the trip. Any fever or joint pain during or after the trip means a doctor visit, and you tell the doctor you were in Guanacaste, Costa Rica.

Traveler questions

Should I get the chikungunya vaccine for Tamarindo?

Ask a travel clinic, 4–6 weeks before departure. CDC recommends chikungunya vaccination for travelers visiting an area with a chikungunya outbreak, and its Level 2 notice for northwest Costa Rica includes Guanacaste. Whether it fits your trip depends on your dates, plans and health, and the notice could be updated or lifted, so check it again the week before you fly.

Are there mosquitoes in Tamarindo in the dry season?

Few. Residents report very few mosquitoes on the Pacific coast from January to early April. Homes near riverbeds and estuaries keep some even then, and beach no-see-ums still bite at dawn and dusk. Spray feet, ankles and calves before a sunset walk.

Do I need malaria pills for Guanacaste?

No. The CDC recommends no malaria medicine for Guanacaste, only bite precautions. It lists prevention medicine for Alajuela and Limón provinces, so if your route continues to Arenal or the Caribbean coast, see a travel clinic 4–6 weeks before departure. The CDC doesn't recommend the yellow fever vaccine for Costa Rica.

Is it safe to visit Guanacaste while pregnant?

CDC advises pregnant travelers to reconsider travel to the areas covered by its chikungunya notice, particularly close to delivery, and Guanacaste is one of them. Talk to a healthcare provider before you book, and check whether the notice is still active.

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