Mexico's bug risk changes with the map, and winter is the easy season

A beach week in Cancún, a long weekend in Los Cabos and a ruins trip to Palenque all count as a trip to Mexico, and they ask different things of your bug spray. On both coasts the issue is dengue, carried by a day-biting mosquito, and a daily routine handles it. In the southern jungles of Chiapas and Campeche, the CDC adds a malaria recommendation, and that one belongs with a travel clinic. Mexico City, at about 7,350 feet, sits above nearly all of it.

Dengue is the routine on both coasts

Dengue is endemic across central and southern Mexico, including the resort states on the Caribbean and Pacific coasts, and the CDC classes the country's risk as frequent or continuous. The northern border states see sporadic outbreaks. In Mexico City, the CDC rates the risk as minimal because of the altitude.

2026 has been a quieter year. National surveillance counted 3,174 confirmed cases through early July, against 4,945 at the same point in 2025. The busiest state has been Sonora, in the northwest, which reported more than 1,800 confirmed cases by mid-October. Jalisco, home to Puerto Vallarta, has reported far fewer cases than in 2025. In Quintana Roo, home to Cancún, the count was still climbing as of mid-September.

The routine still matters. In 2024, Mexico was the most frequent destination among US travelers who came home with dengue, with 892 cases, about a quarter of the total, according to a CDC report published in May 2026. The mosquito behind it, Aedes, bites in daylight, with peaks after sunrise and in the late afternoon, so night-time caution alone misses it. Put repellent on over sunscreen at breakfast, then reapply after swimming and again before sunset. EPA-registered options include picaridin 20%, DEET 20–30%, oil of lemon eucalyptus or PMD at 30%, and IR3535. Our dengue & Zika daily routine has the full schedule, and picaridin vs DEET helps you choose a bottle.

Where you're staying

The scores shift a lot from region to region. Quintana Roo, which holds Cancún, Playa del Carmen, Tulum and Cozumel, is the most visited part of the country, and our Cancún & Riviera Maya briefing covers it in detail, from the Hotel Zone's beach and lagoon sides to Tulum's cenotes. Here is how the main areas compare for a winter trip.

Malaria: three areas and a clinic visit

Malaria in Mexico is limited, and all of it is the P. vivax type. The CDC recommends prevention medicine for three areas: Campeche, Chiapas (including Palenque and San Cristóbal) and southern Chihuahua. Oaxaca, Sinaloa, Sonora and Tabasco see rare or occasional cases, and there the CDC recommends bite precautions without prevention medicine. Along the US border there is usually no transmission. The mosquitoes that carry malaria bite from dusk to dawn, so evenings and nights are when the precautions count.

Chikungunya, Zika and pregnancy

Chikungunya spreads through the same daytime mosquito as dengue and is present in Mexico at low levels. Locally acquired cases are concentrated in Chiapas and Quintana Roo. Through early April 2026, Mexico had 15 confirmed local cases, 9 in Chiapas and 6 in Quintana Roo, and no deaths. There is no CDC chikungunya notice for Mexico. The CDC says the vaccine may be considered for stays of about six months or more, so raise it with a travel clinic if you're planning a long stay.

Zika risk is present but low. The last major outbreak was in 2016, the risk in Mexico City is minimal, and there is no active Zika travel notice. The CDC advises pregnant travelers to talk with a healthcare provider about the trip and to strictly prevent both mosquito bites and sexual transmission.

The one CDC notice is about ticks

The only Mexico-specific CDC travel notice in effect is a Level 1 notice for Rocky Mountain spotted fever, dated December 23, 2025. The disease is spread by dog ticks, and the notice covers the northern border states of Baja California, Sonora, Chihuahua, Coahuila and Nuevo León, including Tijuana, Tecate, Mexicali, Hermosillo and Ciudad Juárez. Los Cabos is in Baja California Sur, which is not on the list. If you're in those states, use repellent, check yourself for ticks every day and avoid contact with dogs.

One more non-mosquito item. New World screwworm, a fly whose larvae infest wounds, is in an ongoing outbreak in Mexico and Central America, mostly among animals. The CDC rates the risk to people as very low. Keep cuts clean and covered, use repellent, avoid sleeping outdoors in the daytime and limit time around livestock.

Winter is the low season

The CDC puts Mexico's dengue peak at May through November, with transmission year-round in the center and south. December to April is the dry season on both coasts and the low point for dengue. Lower risk is still some risk, and Aedes keep biting by day, especially after an unseasonal rain.

Los Cabos runs a little later. Dengue in Baja California Sur builds after the late-summer and fall rains, and the 2025–26 season was still adding cases from January to March 2026, when the state's total passed 700, according to state figures reported in the local press. An early-December trip after a wet fall can catch the tail end. The state had a much larger outbreak in 2024, with 2,618 cases.

In late October 2026, PAHO reported dengue rising again in Central America and flagged an expected El Niño intensification. If your trip is still weeks away, check the CDC's Mexico page again shortly before you fly.

What travelers report from the Caribbean coast

Paraphrased from forum threads and reviews, newest first, and linked so you can read them in full. All of them come from Quintana Roo's Caribbean coast, from Cancún to Tulum, which has its own briefing. Individual trips vary with weather, wind and where you stay.

• Akumal (Grand Sirenis Riviera Maya resort) · November · 2025

  A guest rated the hotel highly and named mosquitoes as the only downside of the stay. TripAdvisor ↗

• Cancún Hotel Zone · January · 2025

  A traveler who stayed in the Hotel Zone in January 2025 reported no bites. TripAdvisor ↗

• Secrets Tulum · June · 2024

  A 2024 reviewer described heavy mosquito problems after rain during a June stay. TripAdvisor ↗

• Cancún area (incl. Puerto Morelos) · January

  Forum replies described January as a low-mosquito month for the area, adding that rain in the preceding weeks makes a difference. Several January visitors, including one at a Puerto Morelos resort, reported no mosquito problems. TripAdvisor ↗

• Riviera Maya (general)

  A poster said mosquitoes are not spread evenly across the region. Resorts with lots of irrigated vegetation have more, and they get worse the farther you are from the coastal breeze. Most posters advised bringing repellent anyway. TripAdvisor ↗

• Playa del Carmen

  A poster said that in their opinion no-see-ums are a worse problem than mosquitoes. TripAdvisor ↗

Keep one rule after you get home. A fever during the trip or within two weeks of returning means a doctor visit, and you tell the doctor you were in Mexico and which regions you visited. That detail gets you the right tests quickly.

Traveler questions