Puerto Vallarta's winter bites come from tiny midges at the beach.

Are there mosquitoes in Puerto Vallarta? A few, and fewer in the dry winter. Dengue is endemic on this coast, but Jalisco has reported far fewer cases in 2026 than in 2025. The bites most visitors notice come from jejenes, tiny biting midges that Americans call no-see-ums, at dawn and dusk near the beach and fresh water.

Dengue is low this year

Mexico's health ministry counted 242 confirmed dengue cases and 2 deaths in Jalisco through mid-October 2026, against 1,741 at the same point in 2025. Nayarit, which holds the Riviera Nayarit beach towns, had 207, a little below its 247 at the same point in 2025. Neither Puerto Vallarta nor Bahía de Banderas, the Nayarit municipality that takes in Nuevo Vallarta, Bucerías, Sayulita and Punta Mita, is among the municipalities the ministry names for 2026. From January to late April 2026, Jalisco had 23 confirmed cases and Nayarit 53.

This coast has had big years, so the routine still matters. In 2019 Jalisco had 11,727 confirmed cases and Mexico's highest incidence. In 2024 Jalisco had 20,907 and Nayarit 5,635, with 1,126 in Bahía de Banderas. The dengue mosquito bites in daylight, so put repellent on over sunscreen in the morning and again after swimming. Shaded, humid forest on the south shore and in the foothills tends to hold more mosquitoes than the Malecón, so jungle and canopy tours deserve a fresh coat.

Mexico's weekly bulletin reported no chikungunya, Zika, West Nile or malaria in Jalisco or Nayarit through early October 2026. Neither state appears among the CDC's malaria areas for Mexico, and the CDC does not recommend the yellow fever vaccine.

Jejenes at dawn and dusk

Jejenes are weak fliers that go for ankles and lower legs at dawn and dusk, and a breeze grounds them. On this coast they tend to bite near the beach and fresh water, and Boca de Tomatlán, the boat launch for Las Animas and Yelapa, has a reputation for them. The beaches at Sayulita, Bucerías and San Pancho are likely spots too, and so is any beachfront table at sunset.

Picaridin and DEET both deter them. Spray feet, ankles and calves before a sunrise walk, a sunset drink or dinner on the sand, and reapply before the boat to the south shore. Sleep in an air-conditioned or screened room, or run a fan at night. Our Barbados sand fly guide explains how the midges behave.

Where you're going

How the main bases compare for a December–April trip.

Adding the Caribbean side? Our Cancún & Riviera Maya briefing covers Quintana Roo, where 2026 dengue is running higher, and the Mexico briefing compares every region.

What travelers report

Paraphrased from TripAdvisor forum threads and linked so you can read them in full. None is dated, and midge bites vary a lot with the weather, the wind and where you stay.

• Puerto Vallarta (Boca de Tomatlán and other beaches) · dusk

  Posters linked the bites to tiny biting midges that locals call jejenes, which often go unnoticed at first, then itch and burn and leave red spots for days. One said DEET repellent works if used at dusk, another said Benadryl gel helped, and posters named San Blas and Boca among the places they had met them. TripAdvisor ↗

• Puerto Vallarta beaches · early morning and dusk

  An advice post said no-see-ums are usually only bad early in the morning and at dusk, and suggested staying away from the beach and fresh water at those times. TripAdvisor ↗

• Puerto Vallarta

  Posters said no-see-ums seem to come and go: one had a quiet trip while another was bitten heavily, and members suggested weather, humidity and where you stay make the difference. TripAdvisor ↗

• Sayulita · January

  A poster said January is typically not a mosquito month. Another said any bites are most likely at night under the table while eating and suggested bug spray on the ankles at dinner. TripAdvisor ↗

• Sayulita · December to June (dry season)

  A resident-type poster said mosquitoes are worst in the rainy season and less common from December to June. Others said they are most active at dusk and dawn and that bedroom fans and permethrin-treated nets help. TripAdvisor ↗

One rule outlasts the trip. Any fever during or after your trip means a doctor visit, and you tell them you were in Puerto Vallarta or the Riviera Nayarit.

Traveler questions