Are there mosquitoes on the Big Island? Few at the resorts, more in South Kona.

Yes, though the dry Kohala resorts see few. Hawaii Island is the only island where both dengue mosquitoes are known, the Asian tiger mosquito islandwide and Aedes aegypti mostly on the western side, and South Kona's shady bays and parks bite more than the lava-coast resorts. The trip needs no vaccine or medicine, and our Hawaii briefing covers Hilo, Volcanoes and the other islands.

The 2015–16 outbreak on the Kona coast

On October 21, 2015, the state health department learned of a positive dengue test in a woman who hadn't left the island, and three days later of a group of mainland US visitors who had traveled together on the island, several with fever, CDC's Morbidity and Mortality Weekly Report recounted. The final count, published in Public Health Reports in 2020, was 264 confirmed cases with onsets from September 2015 to March 2016. About 26 were visitors, 37 people were hospitalized, and no one developed severe dengue or died.

The first case's mosquito contact was most likely near Kona, and the outbreak spread along the populated west coast near Kailua-Kona, Captain Cook and Milolii, a 2020 study in the American Journal of Tropical Medicine and Hygiene found. Near Milolii, where homes store rainwater, Aedes aegypti made up 94% of the mosquitoes caught at three case sites, and both species turned up at Hookena Beach Park, a possible exposure site early on. Among cases, risk factors included holes in window or door screens, standing water, and skipping repellent or protective clothing.

There has been no local spread since, and the travel-related cases in recent press reports have been on Oahu, Maui and Kauai. Statewide, CDC's provisional weekly tables listed 9 dengue cases reported by Hawaii through mid-October 2026, none of them severe. If you arrive from a Pacific island with dengue, or a fever starts during your stay, see a doctor and say where you've been. On this island, that also helps stop a local outbreak before it starts.

Where the bites are

The Kona-Kohala resort coast is dry lava and tends to see few bites. An evening coat of repellent usually covers it, since the night-biting southern house mosquito, a Culex, comes out after dusk. Bites pick up in shade and greenery and toward South Kona. Outbreak trapping found only tiger mosquitoes in Kona-area neighborhoods such as Kealakehe and Wonderview, while Milolii keeps both dengue mosquitoes in every season, a 2023 study in the Journal of Medical Entomology found.

For Kealakekua Bay, Puuhonua o Honaunau, Hookena and Milolii, put repellent on by day as well, especially in shade and after rain, since both dengue mosquitoes bite in daylight. If you rent a house, keep screens shut or use the air-conditioning, and tip out standing water in buckets and plant saucers. Maunakea's summit and visitor station sit far above the elevation where Culex mosquitoes thin out in Hawaii, about 4,900 feet (1,500 m).

The season shifts the picture a little. Hawaii Island's drier summer runs May to October and its wetter winter November to April, and Aedes numbers tend to spike shortly after the wet season or heavy rain. The coffee slopes above Kona and Captain Cook tend to catch afternoon clouds and showers, while the Kohala coast tends to stay sunny. The 2015–16 outbreak ran from September through March, so a winter trip is no safer for dengue.

Where you're going

How the main stops compare, in any month.

Adding Oahu? Our Oahu briefing covers Waikiki and the valley trails behind Honolulu.

One rule outlasts the trip. Any fever during or after your trip means a doctor visit, and you tell them you were on Hawaii Island, and anywhere else you went. Our guide to bites in a dengue zone lists the symptoms to watch for.

Traveler questions