One island, two health systems and the same sand flies.

Yes, though most bites on St. Maarten / St. Martin come at the edges of the day. Sand flies bite on sandy beaches around sunrise and sunset in any month, and mosquitoes come out for a few days after rain. Dengue is present on both sides of the island, there is no malaria, and the French side has been calm for dengue since May 2026.

Dengue on both sides of the border

The island is split between Dutch Sint Maarten, home to Philipsburg, Simpson Bay and Maho, and French Saint-Martin, home to Orient Bay and Grand Case. Each side has its own CDC page, and both list dengue and Zika. Neither has a CDC travel notice, and neither is on the CDC's global dengue list.

The French side has the clearer numbers. Santé publique France, the national public health agency, found no confirmed dengue case on Saint-Martin in the four weeks before its September 10, 2026 bulletin and has called the situation calm since May, the sporadic-case phase of the French dengue plan. The Pan American Health Organization counted seven suspected cases there through early May. The last dengue epidemic declared on the French side was in early 2020.

The Dutch side publishes less. Collective Prevention Services, the public health service there, issued advisories after heavy rain in 2026 that cited the Pan American Health Organization's regional dengue and chikungunya alerts without giving local case counts. It warns that rain, heat and dense housing help Aedes aegypti breed. The last rise flagged on the Dutch side was in January 2024. The mosquito bites by day, with peaks after sunrise and in the late afternoon, so the habit is the same on both sides. Repellent goes on over sunscreen when you head out, again after a swim, and more strictly for a few days after rain. Our dengue & Zika daily routine has the full schedule.

Sand flies, rain and where you stay

The bites most visitors notice come at beach level. Sand flies, the tiny biting midges Americans call no-see-ums, come out on sandy beaches around sunrise and sunset and go for ankles and lower legs. They're weak fliers, so a breeze keeps them down. Grand Case's beachfront restaurants put dinner right in those hours, and Orient Bay has a reputation for sand flies on calm mornings and evenings. Spray feet, ankles and calves before you sit down, and wear light long pants for a table on the sand. Our Barbados sand fly guide explains the insect in detail.

Mosquitoes follow rain. December to April is the drier season, so they're usually fewer, but a winter downpour can bring them out for a few days. Cruise passengers on a daytime Philipsburg call face little exposure, and a small bottle in the day bag covers it.

Where you're going

Here is how the main areas on each side compare for a December–April trip.

One rule outlasts the trip. Any fever during or after your trip means a doctor visit, and you tell them you were on St. Maarten / St. Martin. Heading to the British Virgin Islands for a charter? Our BVI briefing covers bugs at anchor.

What travelers report

Paraphrased from a forum thread and linked so you can read it in full. Rain, wind and where you stay change the picture from one trip to the next.

• St. Martin / St. Maarten (general; Little Bay) · after rain; sunrise and sunset

  Replies said mosquitoes come out when it rains, as they do anywhere, and that a lot depends on where you stay; a poster at Little Bay had no problems. Another reply said many bites people blame on mosquitoes are really from sand flies (no-see-ums) and advised avoiding sandy areas around sunrise and sunset. TripAdvisor ↗

Traveler questions