Weather
Japan is hot in August, whichever way you look at it and wherever you go. But some places are hotter and more uncomfortable than others. Sapporo, capital of the northern island of Hokkaido, sees an average August high of 79°F (26°C) and a low of 66°F (19°C). The major cities of Tokyo, Osaka, Kyoto, and Fukuoka experience highs around 90°F (33°C), and lows of 77°F (25°C), so even overnight, you're going to sweat. Average temperatures in Naha, the capital of Okinawa, are the same.
The good news is that despite high humidity, rainfall tends not to be in August. The exception is when the typhoon season comes a bit early. Japan actually has two wet seasons: the first in June-July, and the second at the end of summer, usually falling in September but sometimes in late August.
Crowds & Costs
Although many international travelers avoid much of Japan in August, this is peak domestic travel time, with schools on vacation. Plus, the important Obon festival falls for a few days in mid-August, and many people take this time off work. In August, families head to beaches, parks, amusement parks, campgrounds, and other places of interest for kids and youngsters, so expect crowds in many places.
Hokkaido is an especially popular summer destination because it's cooler than most other places, and Okinawa is popular for its beaches. If you plan to travel to either of these places, book travel and accommodation as far in advance as possible.
Where to Go
Many places in Japan are likely to be busy throughout August, so it will be hard to avoid crowds at popular attractions throughout the country. But if you'd like to avoid the busiest crowds, check out the Tohoku region of northern Honshu. It's cooler than the southern parts of Honshu, but more easily accessible from Tokyo than Hokkaido. There are many beautiful natural attractions and national parks, and the main city of Sendai may just be Japan's most underrated large city.
August is peak season in Okinawa because of its beautiful beaches, but it's very popular, and it's not the only place in the country to find lovely island beaches. For some quieter alternatives, check out the islands of the Seto Inland Sea—between Honshu, Kyushu, and Shikoku—or those off the north, west, and south of Kyushu.
To escape the heat, you'll either need to go north or go high. Japan is a country with many mountains, so there are many options for the latter. The Japan Alps are a popular hiking destination, running through the middle of Honshu. Nikko and the Nikko National Park are an easy trip from Tokyo, and offer UNESCO World Heritage Sites as well as a cooler climate at altitude.
Chat with a local specialist who can help organize your trip.
What to Do
The Mount Fuji climbing season officially runs from July 1 until September 14, so conditions in August are usually excellent for the climb. While this is hardly an off-the-beaten-path wilderness experience (there are drinks vending machines near the summit!), it's challenging and shouldn't be taken lightly. Travelers with reasonable fitness and hiking experience will enjoy it most, and the views from the top are worth the effort. If you'd prefer to ease yourself in and take your time with the climb, you don't have to start partway up the mountain (base 5), as most climbers do. Instead, you can begin farther down (from base 0), and walk through the forests and past temples, on the longer, more traditional way to the summit.
Events in August
Fireworks, Nationwide. Through July and August, many cities and towns put on summer fireworks displays. Larger cities, such as Tokyo, can be spectacular. Take a blanket to a park or the banks of a river and expect well-managed crowds and fireworks that just keep going on and on. Young women often dress in yukata, a summer kimono. Even smaller towns tend to have their own displays.
Natsu Matsuri, Nationwide. Japanese summer festivals, or natsu matsuri, are held in many towns, cities, neighborhoods, and even small local streets throughout the country, all summer long. These usually include traditional dancing, music and costumes, portable shrines, large crowds, and plenty of food and drink.
Obon, Nationwide. Obon is a three-day festival held in mid-August to honor the dead. Graves are tidied, and people remember their deceased loved ones with offerings of candles. This is one of Japan's most important holidays, and many people take vacation at this time.
Traveling to Japan in August? Check out these great itineraries
Explore Japan's Islands - 10 Days. This itinerary focuses on a side of Japan that few travelers see: the remote islands surrounding the main islands. Stargaze on Hachijojima, admire the volcano on Aogashima, and much more.
Magic of Japan: Tokyo, Kyoto, Hiroshima - 12 Days. Discover Japan's traditional and modern sides as you visit shrines and temples, witness technological innovation at an amazing digital art exhibition, and attend a crazy robot show.
More Helpful Information
Japan in July
Japan in September
Best Time to Visit Japan
How Many Days Should You Spend in Japan?
Guide to Japan's Main Regions