No malaria pills for Siem Reap or Angkor Wat. Cambodia's dengue epidemic is the reason to put repellent on before sunrise.
- CDC Level 1 Global dengue (Cambodia listed)
- Travel clinic CDC recommends medicine or vaccines for some areas · which ones
The CDC reports no or negligible malaria in Siem Reap and at the main temple complex at Angkor Wat. Cambodia's 2026 dengue count passed 110,000 cases by early October, and the mosquito that spreads it bites in daylight, from the sunrise visit on.
Yes, and in 2026 they matter more than usual. Cambodia is in a dengue epidemic year, and the Aedes mosquito that spreads dengue bites in daylight, from the sunrise visit at Angkor Wat through the afternoon at Ta Prohm. Malaria is a narrower question. The CDC reports "no (or negligible) malaria transmission" in Siem Reap and at the main temple complex at Angkor Wat, and recommends no medicine for either.
A dengue epidemic year
The World Health Organization's Western Pacific office, reporting figures from Cambodia's national dengue surveillance system, counted 110,850 cases and 118 deaths by October 4, 2026, 138% above the same point in 2025. Weekly cases have fallen since a late-August peak, but WHO said "case counts remained far above the epidemic threshold." Those figures are national, but the Cambodian news outlet Cambodianess reported in late September that Siem Reap's Jayavarman VII Children's Hospital was treating some dengue patients on the floor.
The classic Angkor day lines up with the mosquito's schedule. Sunrise at Angkor Wat puts you beside the moat as its morning peak begins, the shady jungle temples keep you in its hours all day, and the late-afternoon peak lands on sunset. Put repellent on over sunscreen before you leave the hotel in the dark and reapply through the day. Light long sleeves and trousers, which the temple dress code asks for anyway, help too. Our dengue & Zika routine has the full schedule.
Malaria: Angkor Wat is exempt, the forest temples are a question
Malaria is at very low levels nationally. The WHO's Mekong Malaria Elimination Programme counted 355 confirmed cases nationwide in 2024 and 98 from January to September 2025, with no malaria deaths. The CDC says transmission is "primarily isolated to pockets in rural and forested areas."
The CDC's wording. It reports "No (or negligible) malaria transmission in the cities of Phnom Penh (the capital) and Siem Reap" and "No (or negligible) malaria transmission at the main temple complex at Angkor Wat." For "Rural and forested areas" it lists "Atovaquone-proguanil, doxycycline, primaquine, tafenoquine." The exemption names only the main temple complex at Angkor Wat. The CDC doesn't say whether the rest of the archaeological park, the outlying forest temples (Phnom Kulen, Kbal Spean, Beng Mealea, Koh Ker) or the Tonlé Sap villages count as rural and forested. If any of them are in your plan, book a travel-medicine appointment 4–6 weeks before departure and bring the route, night by night. Our malaria-zone checklist covers the rest.
Ask about Japanese encephalitis vaccine at the same visit if you'll sleep in a Tonlé Sap village or near the forest temples. The CDC suggests considering it for shorter trips with rural stays or unscreened nights. Rabies isn't spread by insects, but the CDC says "Dogs infected with rabies are commonly found in Cambodia," so keep clear of temple dogs and monkeys. Yellow fever vaccine is not recommended.
When to go
The dry season, roughly December to April, is usually the easiest time, and July to September the hardest. Whether this year's epidemic will have wound down by the December high season is unknown, so plan on the daytime routine whatever month you go.
Where you're going
Angkor Wat, Angkor Thom & the Bayon
The CDC reports no (or negligible) malaria at the main temple complex at Angkor Wat. Sunrise puts you beside the moat as the day-biting mosquito's morning peak begins, so put repellent on before you leave the hotel.
Ta Prohm, Preah Khan & the jungle temples
Shady, humid temples inside the archaeological park, and a full day in dengue-mosquito hours. The CDC's malaria exemption names only the main temple complex at Angkor Wat, so list these too when you describe the route to a clinic.
Phnom Kulen, Kbal Spean, Beng Mealea & Koh Ker
Outlying forest temples. If they count as "rural and forested areas," the CDC lists prevention medicine for them, and its wording doesn't say. Take the plan to a travel clinic 4–6 weeks before departure.
Tonlé Sap floating villages
Daytime boat trips to stilt villages, with mosquitoes tending to pick up toward dusk. The CDC's malaria wording doesn't address the villages, and a homestay is the kind of rural night where it suggests considering Japanese encephalitis vaccine.
Adding Phnom Penh or the coast? The Cambodia briefing covers the rest of the country. Crossing into Thailand? Our Thailand briefing covers the CDC's malaria advice for its Cambodian border provinces.
The Angkor kit
- Picaridin 20% travel sprays: odorless in the heat and layers over sunscreen for a sunrise-to-sunset temple day. One 3.4 oz bottle covers about a week of daily use for one person.
- Permethrin 0.5% for temple clothes: treat the long-sleeved shirt and light trousers you'll wear for the dress code at home, 48 hours before you fly. Fabric only, never skin.
What travelers report
Paraphrased from TripAdvisor forum threads and linked so you can read them in full. None is dated and some may be several years old, so the season and where you stay can change the picture.
- Angkor Wat at sunrise and sunset · July
Asked about mosquitoes at Angkor at dawn and dusk, posters said bites were not a major problem on a July sunset visit; the advice was to use repellent and cover up. TripAdvisor ↗
- Angkor Wat at sunrise · sunrise
In a thread about mosquitoes at Angkor Wat, a poster said the worst time was from about an hour before sunrise to an hour after, and another noted the temple is surrounded by a large body of standing water, so some mosquitoes are to be expected. TripAdvisor ↗
- Siem Reap hotels
Posters said air conditioning and closed windows and bathroom doors keep most mosquitoes out of rooms, but gaps under doors, dark hallways and unscreened bathroom fans let them in; one suggested spraying the room before going out, since cleaning staff leave doors open. TripAdvisor ↗
The CDC lists Zika for Cambodia, including spread from a pregnant woman to her baby, so if you're pregnant, review its Zika guidance with a healthcare provider before you book. And any fever during or after your trip means a doctor visit, and you tell them you were in Cambodia.
Traveler questions
Do I need malaria pills for Angkor Wat?
The CDC reports "No (or negligible) malaria transmission at the main temple complex at Angkor Wat" and in the cities of Siem Reap and Phnom Penh, and lists prevention medicine only for "Rural and forested areas." The exemption names only the main complex. If your plans include the outlying forest temples, a rural homestay or a night in a Tonlé Sap village, take the route to a travel clinic 4–6 weeks before departure. Our malaria-zone checklist covers the rest.
Is dengue bad in Siem Reap right now?
Cambodia is in an epidemic year. The World Health Organization counted 110,850 cases and 118 deaths nationwide by October 4, 2026, 138% above the same point in 2025. Weekly cases have fallen since late August but remain far above the epidemic threshold. WHO doesn't break the count down by province, but in late September the Cambodian news outlet Cambodianess reported that Siem Reap's main children's hospital was treating some dengue patients on the floor. Repellent goes on before the sunrise visit and again through the day.
What about Phnom Kulen, Beng Mealea or a Tonlé Sap homestay?
The CDC doesn't say whether outlying forest temples or the Tonlé Sap villages count as "Rural and forested areas," where it lists atovaquone-proguanil, doxycycline, primaquine or tafenoquine. Malaria is at very low levels nationally, with 355 confirmed cases in 2024, according to the WHO's Mekong program, but whether medicine fits your route is a call for a travel clinic. Ask about Japanese encephalitis vaccine at the same visit if you'll sleep in a village.
When is the best time to visit Angkor for fewer mosquitoes?
Roughly December to April, the dry season. The rainy months, roughly May to October, are harder, and July to September the worst. In 2026 the open question is whether the epidemic will have wound down by the December high season, since weekly cases were falling in early October but still far above the threshold. Plan on daytime repellent whatever month you go.
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.