When is the rainy season in Japan?

Tsuyu brings weeks of damp, gray weather to most of Japan each early summer, and this guide explains the dates, the regional differences and how to plan around it.

Published October 21, 2026 at 7:27 AM JST | By Tokyo Paul

Quick answer: The rainy season (tsuyu, also called plum rain) usually runs from early June to mid July in most of Japan, lasting about five to six weeks. Okinawa's season starts earlier, from about May to mid June, and Hokkaido is mostly spared. Exact start and end dates vary each year and by region, so check the Japan Meteorological Agency.

What tsuyu is and when it happens

Tsuyu (written with characters meaning "plum rain") is the rainy season that sweeps across much of East Asia in early summer. In Japan it usually brings long stretches of cloudy, damp weather with frequent rain, high humidity and occasional heavy downpours, rather than constant rain every hour of every day.

According to a general reference on the East Asian rainy season, the main islands of Honshu, Shikoku and Kyushu usually see it from early June to mid July. For Kanto and Kansai, the dates are described as roughly June 7 to July 20, a span of about six weeks. The season is also called samidare.

The national tourism organization says the rainy season begins in May to June, which fits with the way the front moves north from the southwest over several weeks. Treat all these dates as typical, not fixed.

Regional differences

Okinawa's rainy season comes about a month earlier than the main islands, from early May to mid June in the reference article. Rain there is described as less continuous than on the mainland. Southern Kyushu typically starts before Tokyo, and the season ends earlier in the south than in the north.

Hokkaido has no pronounced rainy season. The rain front usually weakens before reaching the island, so it does not bring much rain, and a general climate reference confirms that Hokkaido is not affected. That makes Hokkaido a popular early summer choice for travelers who want to avoid the damp.

On the main islands, the experience also varies by area. Some years the front stalls over a region and brings repeated heavy rain, while in other years the season is shorter or lighter. The reference article notes that the season can bring heavy rain, so it is wise to follow official warnings during your stay.

How the start and end are announced

The Japan Meteorological Agency (JMA) typically announces the start and end of the rainy season for each region, such as Kanto-Koshin or Kinki. These announcements are based on the weather pattern and can be revised after the season ends, so the exact dates people hear are best treated as approximate markers.

Because the weather is variable, the first rainy days may not match the official start, and the end does not always mean the end of rain. Some years have "empty" rainy seasons with relatively little rain, and in others the rain continues into a heavy downpour period near the end.

For planning, the JMA's forecasts and the local weather outlook a week or two before your trip are more useful than an exact calendar date. The JMA also provides English pages on climate and warnings.

Practical planning: what to pack and do

Bring a compact umbrella or a light rain jacket, waterproof or quick-drying shoes, and a spare pair of socks. Choose breathable, quick-drying fabrics, since humidity can be high even when it is not raining. A small towel and a waterproof cover for your bag can also help.

Plan flexible itineraries with plenty of indoor options such as museums, aquariums, department stores, covered arcades and hot springs. Many temples and gardens are especially green and atmospheric after rain, and hydrangeas are a seasonal highlight, although individual flowering times vary.

Keep your schedule loose, so you can move outdoor activities to the clearer days. Allow extra time for transport on days of heavy rain, because trains and roads can be delayed, and check official notices if heavy rain warnings are issued.

Who it suits and special cases

Travelers who dislike crowds sometimes choose early June precisely because it can be quieter than spring or autumn, when the most famous sights are busiest. Prices for flights and hotels can be lower outside the major holiday weeks, though this varies by year. Photographers may enjoy green hillsides, misty mountains and reflections in wet streets.

Families with young children, older travelers and anyone using a wheelchair or stroller may find rainy days more demanding, because paths can be slippery. Choose destinations with covered walkways or indoor attractions, and plan shorter outdoor stretches.

Hikers should be careful, since rain can make trails muddy and slippery, and heavy rain can raise the risk of landslides and swollen rivers. Check the mountain weather forecast and local advice before any hike.

Common mistakes and misunderstandings

One mistake is assuming it rains all day every day. Many rainy season days are cloudy with intermittent showers, and some days are dry or even sunny. Another is believing the dates are the same everywhere. As described above, Okinawa's season is earlier, the mainland follows, and Hokkaido is mostly spared.

Some visitors skip Japan altogether in June, but there are advantages, including lush scenery and thinner crowds at many sights. It is also a mistake to forget about humidity and heat at the end of the season, when temperatures rise and the air stays damp.

Finally, do not rely only on last year's start and end dates. The pattern shifts from year to year, and the best information comes from current forecasts and from official announcements made as the season begins and ends in each region.

Planning tips and next steps

Check the JMA's forecast about a week before your trip and again each morning. Book accommodation with flexible cancellation if possible, and consider spending part of your trip in Hokkaido, where the rainy season is mostly absent, or in Okinawa if you travel after mid June.

Pack light, bring a rain layer and leave space in your schedule for a flexible day. The national tourism organization notes that summer follows with extreme heat and high humidity, so expect warmer, stickier conditions as July progresses, and bring clothing you can change easily during the day.

If you would rather avoid the rain, spring and autumn are generally drier, and a trip to Hokkaido in June offers a pleasant alternative. This guide shares general information; rules change, so confirm details with the official agency or provider before you act.

Frequently Asked Questions

Does it rain every day during Japan's rainy season?

No. Rain is frequent, but many days bring only light showers or cloudy skies, and some are dry. The pattern varies by year and region, with occasional heavy downpours, so carry an umbrella and keep plans flexible.

Is June a bad month to visit Japan?

Not necessarily. June is often damp and humid, but it can also be quieter and greener than the peak seasons. Plan indoor alternatives, pack rain gear, and consider Hokkaido, which is mostly spared from the rainy season.

Is there a rainy season in Hokkaido?

Hokkaido has no pronounced rainy season, since the rain front usually weakens before reaching the island. It can still rain, but the long gray spell seen on Honshu is generally absent, according to climate references.

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