Sri Lanka has had a very large dengue year. Here's what it means for your trip.
More than 100,000 dengue cases by late September 2026, over half of them in the Western Province around Colombo, put Sri Lanka on the CDC's global dengue list. The island has been malaria-free since 2016, so the job is a daytime repellent habit.
Yes. Mosquitoes are found across most of Sri Lanka, and in 2026 they carried a very large dengue epidemic. The National Dengue Control Unit counted 100,127 cases by September 27, more than half of them in the Western Province around Colombo. There is no malaria, and the CDC lists no malaria medicine for the island, so the protection that matters is a daytime repellent routine.
Dengue in 2026, and chikungunya before it
Sri Lanka is on the CDC's global dengue list, a Level 1 notice for countries with higher-than-usual case numbers. The 2026 epidemic peaked in July, with 29,964 cases that month, and has fallen since, to 10,155 in August and 4,637 in the first 27 days of September. It is still far from normal. In mid-September, weekly cases were about 90% above the same week of 2025, the World Health Organization reported. Colombo and neighboring Gampaha were the most affected districts.
Chikungunya ran through 2025 as well, peaking in June. By the end of August that year, more than half of cases came from the Western Province, and Colombo District alone had a third. In October 2025 it rose again in the north and east, with Jaffna reporting more than 80% of national cases that month.
Both spread through Aedes mosquitoes, which bite in daylight with peaks after sunrise and in the late afternoon. Put repellent on over sunscreen in the morning, reapply after swimming or a sweaty hike, refresh it before sunset and sleep in an air-conditioned or screened room. Our dengue & Zika daily routine has the full schedule.
Where and when the bites are worst
Lowland and lakeside areas, such as Sigiriya and Tissamaharama near Yala National Park, tend to be the buggiest. The cooler hill country around Ella tends to be lighter, though not bite-free, and on the south coast the sea breeze helps. Traveler complaints are mostly about dawn, dusk and evening, and heat and humidity bring more mosquitoes. CDC also lists leishmaniasis, spread by sand flies that bite from dusk to dawn, which is one more reason for long sleeves on evening safaris and lakeside dinners.
For timing, January to April is roughly the best window for Colombo, the south coast and the hill country. The southwest monsoon tends to wet the west and south coasts from about May to September, and May to August on the west coast is the hardest stretch, the months when the 2026 epidemic peaked. Jaffna and Trincomalee in the north and east are wettest from October, when chikungunya flared there in 2025.
Colombo
The Western Province had 52.5% of 2026 dengue cases, with Colombo and Gampaha the worst-hit districts, and Colombo District had a third of 2025's chikungunya cases by August that year. Keep the daytime routine strict here.
Galle, Unawatuna & Mirissa
Dengue is present, though the Southern Province wasn't among the top areas in 2026. The sea breeze tends to help on the beach, and dawn and dusk are when bites are most likely.
Kandy
One of three sentinel sites that confirmed chikungunya in early 2025, and a little cooler than the coast. Dengue is endemic here too, so keep the daytime habit.
Ella & the hill country
Cooler and higher, with fewer mosquitoes than the lowlands. Bites still happen in the hills, so pack the same repellent.
The Sri Lanka kit
- Picaridin 20% travel sprays: odorless in the humidity and layers over sunscreen. One 3.4 oz bottle covers about a week of daily use for one person.
- A full-size backup in the checked bag for a two-week loop or a family.
- Permethrin 0.5% for safari and evening clothes: treat a long-sleeved shirt and trousers at home 48 hours before you fly. It goes on fabric, never on skin.
What travelers report
Paraphrased from forum threads and reviews and linked so you can read them in full. Some are years old, and mosquitoes vary a lot with rain, season and where you stay.
- EKHO Safari Tissa, Tissamaharama (near Yala) · August · 2025
A guest described large mosquitoes near the lake and around the buffet area. TripAdvisor ↗
- Jetwing Vil Uyana, Sigiriya · 2011
A guest complained about the number of mosquitoes at this Sigiriya resort. TripAdvisor ↗
- Sri Lanka (island-wide forum thread)
Replies said mosquitoes are found across most of the island and vary a lot by place and season, with fewer in cooler, higher areas such as Ella. One poster disputed that Nuwara Eliya is mosquito-free after being bitten at the golf club, and others said the sea breeze helps on the coast. TripAdvisor ↗
Any fever during or after your trip means a doctor visit, and you tell them you were in Sri Lanka. In a year like this one, that sentence gets you a dengue test quickly.
Traveler questions
Do I need malaria pills for Sri Lanka?
The CDC lists no malaria medicine for Sri Lanka. WHO certified the country malaria-free on September 5, 2016, and there have been no locally acquired cases since October 2012. WHO says imported cases and the mosquitoes still present across the island keep a risk of reintroduction. If you're pairing Sri Lanka with India, where CDC does recommend malaria medicine, see our India briefing and take both legs to a travel clinic.
Is dengue still bad in Colombo?
It's past the peak and still high. Cases fell from 29,964 in July to 4,637 in September 1–27, but in mid-September they were still about 90% above the same week of 2025, the World Health Organization reported. The Western Province, which includes Colombo and Gampaha, had more than half of the year's cases. Treat repellent as a daily habit in the city.
Is it safe to visit Sri Lanka while pregnant?
CDC lists Zika among the bug-borne diseases in Sri Lanka. If you're pregnant, talk to a healthcare provider before you travel.
Do I need a Japanese encephalitis or chikungunya vaccine?
CDC says chikungunya vaccination is generally not recommended for Sri Lanka and that all travelers should prevent mosquito bites. Japanese encephalitis is present, and CDC recommends that vaccine for stays of a month or more in areas with the disease and says to consider it for shorter trips with rural travel, hiking or camping, or lodging without air-conditioning, screens or bed nets. Ask a travel clinic 4–6 weeks before departure if your trip fits. Yellow fever vaccine isn't needed from the US, though Sri Lanka requires it from travelers arriving from a country with yellow fever risk, including layovers of more than 12 hours there.
Sources
Health authorities, surveillance reports and news coverage of official bulletins used for this briefing, last checked October 2026. Traveler reports are linked where they appear. This page summarizes public-health guidance and is not medical advice.
- CDC Travel Health Notice
- European Centre for Disease Prevention and Control
- World Health Organization
- World Health Organization
- World Health Organization
- European Centre for Disease Prevention and Control
- CDC destination page for travelers
- World Health Organization
- World Health Organization
- World Health Organization