Mosquitoes in Mongolia: Summer Lakes, Forest Ticks & the Gobi (2026)

Mongolia has no malaria, dengue or Zika. Mosquitoes and biting flies tend to gather by lakes, rivers and forests in July and August, while ticks in the northern forests can carry tick-borne encephalitis, most of all from April to June.

Yes, in summer, but Mongolia has no malaria, dengue or Zika. Mosquitoes and biting flies tend to gather by lakes, rivers and forests in July and August, at Terelj and Khövsgöl more than in the Gobi. The bite with health stakes comes from ticks in the northern forests, which can carry tick-borne encephalitis (TBE).

Disease risk LowNo malaria, dengue or Zika and no CDC mosquito notice; ticks in the northern forests carry tick-borne encephalitis, mostly from April to June.

Bite nuisance NoticeableMosquitoes and biting flies tend to gather by lakes, rivers and forests in July and August, flies hang around the ger camps, and the Gobi tends to be lighter.

CirculatingTBE ticks (northern forests)Rickettsia & Lyme (ticks)Plague in marmots (west)No malariaNo dengue or Zika mosquitoesNo yellow fever vaccine

CDC noticesNo country-specific notice for mosquito-borne disease

Jun–Sep tripsJune is the tail of the April–June tick season in the northern forests. July, with Naadam, and August tend to bring the most mosquitoes and biting flies near lakes, rivers and forests, and Terelj has a reputation for mosquitoes in late summer. September is cooler, and insects tend to thin out.

Data checkedOctober 2026 · sources

Ticks in the northern forests

The tick that carries TBE, Ixodes persulcatus, lives in Mongolia's northern forests, and the disease has long been described in the forested provinces of Bulgan and Selenge. A 2019 study counted 14 fatal cases from 2008 to 2017, all after tick bites in Bulgan or Selenge between April and June. In 2024 researchers found TBE virus in ticks collected in Töv province, about 52 miles (83 km) from Ulaanbaatar, the closest find to the capital yet documented. Töv is also home to Gorkhi-Terelj National Park, so a forest ride there calls for the tick routine. Ticks in the forests and on the central steppe also carry Rickettsia and the bacteria behind Lyme disease, a 2019 review found.

CDC says the "TBE vaccine is recommended for persons who will have extensive exposure to ticks based on their planned outdoor activities and itinerary" and "may be considered for persons who might engage in outdoor activities in areas ticks are likely to be found." If a horse trek, hiking or camping in the northern forests is on your plan, at Terelj, Khövsgöl, Bulgan or Selenge, ask a travel clinic 4–6 weeks before departure. On the trail, use a repellent with 20% or more DEET, which CDC advises when you need protection from both ticks and mosquitoes; our picaridin vs. DEET comparison explains the trade-offs. Wear permethrin-treated clothes with pants tucked into socks, and check your whole body for ticks every evening, most of all in June.

One animal rule comes with Mongolia. Plague persists in wild rodents in parts of the country, most actively in the west, and the marmot flea is its main carrier, a 2010 review found. Human cases follow hunting, skinning or eating marmots, and a 2020 report described two deaths after people ate raw marmot organs. Don't handle or eat marmots, and leave dead rodents alone.

Mosquitoes and flies by the water

June to September is the main travel season, when the ger camps at Terelj and Khövsgöl are open. July, with the Naadam festival in mid-July, and August tend to bring the most mosquitoes and biting flies around lakes, rivers and forests. Terelj has a reputation for mosquitoes, especially in late summer, and flies have a reputation as a common nuisance at Khövsgöl Lake. Mosquitoes tend to bite most from dusk, so put repellent on before an evening walk by the shore, and keep a head net for still evenings by the water. The Gobi tends to be drier and less buggy, with flies around the camps more of a nuisance than bites. Ulaanbaatar and Naadam's stadium events carry little bite risk.

The shoulder seasons shift the problem. April to June is tick season in the northern forests, so a June trip still needs the tick routine. September is cooler, and insects tend to thin out.

Where you're going

How the four usual stops compare for a June–September trip.

city

Ulaanbaatar & Naadam

Disease risk NegligibleBite nuisance Hardly any

City sightseeing and the Naadam stadium events in July carry little bite risk. Ticks only become a question on forest day trips out of the city.

countryside

Gorkhi-Terelj National Park

Disease risk LowBite nuisance Noticeable

Forest and river country in Töv province near Ulaanbaatar, with a reputation for mosquitoes in late summer. Ticks in Töv carried TBE virus in 2024, so tuck in and do a tick check after a ride or hike.

countryside

Gobi ger camps

Disease risk NegligibleBite nuisance Occasional

Dry desert and steppe that tends to have few mosquitoes, though flies hang around the camps. Wild rodents here can carry plague, so keep away from marmots and any dead animals.

lake

Khövsgöl Lake

Disease risk LowBite nuisance Noticeable

A northern lake in the forest country where the TBE tick lives. Flies have a reputation as a common nuisance here, and lakeshore evenings in July and August tend to call for repellent and a head net.

Adding Beijing or Seoul? Our China and South Korea briefings cover their summers.

The Mongolia kit

For horse treks, forest hikes and lakeside evenings. Ulaanbaatar and the Gobi need little.

Permethrin 0.5% for riding and hiking clothes: treat pants, a long-sleeved shirt and socks at home 48 hours before you fly, for the forests at Terelj and Khövsgöl. It goes on clothing, never on skin.
Picaridin 20% travel sprays for evenings by the lake and in camp. One 3.4 oz bottle covers about a week of daily use for one person, and the size rides in a carry-on.
A fine-mesh head net for still evenings by the water.

Permethrin → Carry-on trio → Full rankings

What travelers report

Paraphrased from TripAdvisor forum threads and a review and linked so you can read them in full. None is dated, and the forum threads are years old, so read them for where the insects are and use the facts above for this season.

Rural Mongolia · spring
A reply in a thread about insects in Mongolia said there are plenty of insects, as in any rural area, but that ticks need the most care, spring is the worst time of year, and many ticks carry Lyme disease or encephalitis. The thread is roughly a decade old. TripAdvisor ↗
Gers on a three-week tour
A traveler reported that spiders were common in the gers during a three-week trip, and another poster added that bedbugs can live in the thick felt of the yurts. TripAdvisor ↗
Terkhiin Tsagaan Nuur National Park (Arkhangai) · summer
A reviewer warned that flies were everywhere, including at the ger camp, and said they did not bite but the noise and constant flying were annoying. TripAdvisor ↗

One more rule outlasts the trip. Any fever, rash or headache during or after your trip means a doctor visit, and you tell them you were in Mongolia and whether a tick bit you.

Traveler questions

Do I need malaria pills or a yellow fever vaccine for Mongolia?

CDC's Mongolia page has no malaria section and lists no malaria medicine. The World Health Organization has listed Mongolia since 1963 among the countries where malaria never existed or disappeared without specific measures. CDC doesn't recommend the yellow fever vaccine for Mongolia, and the country doesn't require it.

Do I need the tick-borne encephalitis vaccine for Mongolia?

It depends on your plans. CDC says the "TBE vaccine is recommended for persons who will have extensive exposure to ticks based on their planned outdoor activities and itinerary" and "may be considered for persons who might engage in outdoor activities in areas ticks are likely to be found." The fatal cases counted from 2008 to 2017 all followed tick bites in the forested Bulgan and Selenge provinces between April and June, and infected ticks turned up in Töv province near Ulaanbaatar in 2024. A city and Gobi trip stays out of the northern forests. For a horse trek or camping at Terelj or Khövsgöl, ask a travel clinic 4–6 weeks before departure.

When are mosquitoes worst at Khövsgöl and Terelj?

July and August tend to be the buggiest months by Mongolia's lakes, rivers and forests, and Terelj has a reputation for mosquitoes in late summer. June tends to be quieter for mosquitoes but is still tick season in the forests. September is cooler, and insects tend to thin out. Repellent for evenings by the water and a head net for still days cover it.

Are there mosquitoes in Ulaanbaatar during Naadam, or in the Gobi?

Few that matter. Ulaanbaatar's sights and the Naadam stadium events in July carry little bite risk, and the dry Gobi tends to have few mosquitoes. Flies around the Gobi ger camps tend to be the bigger nuisance. CDC lists Mongolia among the areas with no mosquitoes that spread Zika, the same Aedes species that spread dengue, so the city needs no daytime repellent routine.

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.

Are there mosquitoes in Mongolia? Yes, by the lakes in summer. The forest ticks matter more.