San Juan del Sur has few mosquitoes and one virus to plan for.

Are there mosquitoes in San Juan del Sur? A few. Nicaragua's Pacific coast has a reputation for fewer mosquitoes than the Caribbean side, and they mostly come out after sunset. Chikungunya is what to plan around. The CDC's Level 2 notice covers the whole country, Rivas department and San Juan del Sur included.

The chikungunya notice, and the numbers behind it

The CDC's notice, last reviewed September 3, 2026, says "There is an outbreak of chikungunya in Nicaragua," and its map shades the entire country. It says "Vaccination is recommended for travelers who are visiting an area with a chikungunya outbreak," and tells pregnant travelers to "reconsider travel to the affected areas, particularly if you are close to delivering your baby."

Nicaragua's health ministry publishes only national weekly counts, with no breakdown by department, so there are no published figures for Rivas or San Juan del Sur. Nationally, the outbreak built from late May and peaked in August, at about 1,840 cases that month in Nicaraguan press tallies of the ministry's releases. The weekly count fell to 199 people diagnosed in the week ending September 19, then rose to 299 in the week ending October 17.

Dengue is endemic too, with 86 people diagnosed nationally in the week ending October 17, and it travels by the same day-biting Aedes mosquito, so one routine covers both. No yellow fever vaccine is recommended, and none is required when you fly direct from the US. The CDC's Nicaragua page also lists New World screwworm and advises cleaning and covering all wounds.

Pool days, surf sessions and evenings on the bay

The chikungunya mosquito lives close to people, around houses, hostels, pools and water tanks, and bites in daylight. Sunday Funday is known as a pool crawl, which means a long, hot afternoon in its territory, with repellent likely sweated and swum off. Put it on over sunscreen in the morning, again in mid-afternoon and after every swim.

On the surf beaches, Maderas and Marsella to the north and Remanso, Hermosa and Yankee to the south, dawn and sunset sessions overlap the hours when beach midges bite in still air. Frommer's warns that at some Nicaraguan beaches visitors will probably be bitten by pirujas, the local name for sand fleas or no-see-ums. The windy early months of the year tend to keep them down by day. Spray feet and ankles before and after a session, and wear long sleeves for evenings at the bay-front bars, when the mosquitoes come out. Choose an air-conditioned or screened room, or sleep under a net in an open-air surf lodge. Our Barbados sand fly guide explains how the midges behave.

Where you're going

Scores are for a December–April trip.

Our Nicaragua briefing covers Granada, Ometepe and the Corn Islands. Crossing into Costa Rica? Guanacaste, just over the border, has a CDC Level 2 chikungunya notice of its own, and by September press coverage of Costa Rica's health ministry put the outbreak's hotspot in La Cruz, the canton on the Nicaraguan border.

What travelers report

Paraphrased from TripAdvisor forum threads and linked so you can read them in full. Neither is dated and both threads are older, so they say nothing about the 2026 outbreak.

• San Juan del Sur · evenings

  A reply in an older thread said the Pacific coast is better than the Caribbean side for mosquitoes and that they only bother people after sunset. TripAdvisor ↗

• San Juan del Sur

  In an older thread about dengue, a poster recommended mosquito netting and plenty of repellent, while noting there is no guarantee against infection. 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 Nicaragua, plus Costa Rica if you crossed the border.

Traveler questions