Japan's summer bites come in the parks, shrines and bamboo groves.

Are there mosquitoes in Japan? Yes, and in summer you'll meet them by day in city parks, on shrine and temple grounds and along wooded paths in Tokyo and Kyoto. They're mostly an itch, because Japan has no malaria, dengue isn't endemic, and the country's one modern dengue outbreak was in Tokyo in 2014.

Tiger mosquitoes in the temple gardens

The biter is the Asian tiger mosquito, Aedes albopictus. A CDC journal analysis describes it at high densities in Japanese cities. It bites by day, with peaks in the morning and late afternoon, and favors shade, which puts it right where sightseers go: wooded shrine and temple grounds, city parks such as Tokyo's Yoyogi, and in Kyoto the Fushimi Inari trail and the Arashiyama bamboo grove. June to September is peak season in Tokyo, Kyoto and Osaka, and the early-summer rainy season and the humid heat of July and August tend to bring the most bites.

Put repellent on over sunscreen before you head out, and again before a late-afternoon garden walk. Picaridin 20%, DEET 20–30%, oil of lemon eucalyptus or PMD 30%, and IR3535 are all EPA-registered options, and our picaridin vs. DEET comparison covers the trade-offs. Wear long pants on wooded trails.

If you'd rather buy repellent at a Japanese drugstore after you land, read the active ingredient and its strength on the label and match it to that list; a translation app helps with Japanese packaging. A mosquito coil or plug-in can help on a ryokan veranda or in a room with the window open, because smoke and vapor work in still, enclosed air. Neither does much on a breezy shrine trail, where repellent on your skin does the job.

Spring and fall are gentler. A spring trip falls before the summer peak, so bites tend to be lighter. The tiger mosquito stays active until about November in most of Japan, though, so an autumn visit to Kyoto's gardens still calls for repellent.

Dengue in 2014, and the encephalitis question

In summer 2014, Tokyo had Japan's first locally acquired dengue since the 1940s, centered on Yoyogi Park. By mid-September, WHO's Western Pacific surveillance journal counted 131 locally acquired cases, 112 of them linked to Yoyogi Park or nearby, and no deaths. The virus also turned up in mosquitoes in Yoyogi and later in Shinjuku Gyoen. A CDC journal analysis of 2011–2016 surveillance found no other epidemic and called Yoyogi probably an unusual event.

Japanese encephalitis is present in Japan, with very few human cases. The CDC recommends the vaccine for travelers moving to Japan, spending a month or more in areas with JE, or traveling there frequently. It says to consider it for shorter trips that include rural areas, hiking or camping, or lodging without air conditioning, screens or bed nets, and it does not recommend it for short-term travel to urban areas. If your trip goes beyond the cities, take your plan to a travel clinic 4–6 weeks before departure. The CDC also lists tick-borne encephalitis, so check yourself for ticks after forest hikes.

Where you're going

Here is how the main stops compare for a June–September trip.

What travelers report

Paraphrased from TripAdvisor reviews from 2016 and 2017, newest first, and linked so you can read them in full. Both are from Kyoto, and the month and time of day change the picture.

• Fushimi Inari-taisha, Kyoto · morning hike · 2017

  A reviewer advised going early and bringing repellent, saying there were lots of mosquitoes along the side of the trail on their morning hike. TripAdvisor ↗

• Arashiyama, Kyoto · 2016

  A reviewer called Arashiyama a must-visit but warned of many mosquitoes in the wooded bamboo area, saying visitors in shorts get bitten and should use DEET. TripAdvisor ↗

One rule outlasts the trip. Any fever during or after your trip means a doctor visit, and you tell them you were in Japan, including any time in the countryside.

Traveler questions