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Japan has two distinct wet periods and they get confused constantly. Tsuyu is a stationary rain front that creeps north over about six weeks. Typhoon season is a tropical storm track that peaks later and behaves nothing like it. One makes a trip damp; the other can cancel your train.
The two seasons
- Tsuyu runs roughly early June to mid-July on the main islands, earlier in Okinawa.
- It is not continuous rain. Expect humidity and rain on many days, not all day every day.
- Typhoon season runs May to October, concentrated in August and September.
- Hokkaido has no true tsuyu and the lowest typhoon exposure in the country.
- Both periods are cheaper and quieter than the seasons on either side.
Tsuyu, region by region
The rain front forms south of the archipelago and moves north, so the dates depend entirely on where you are. These are long-term averages published by the national weather agency; any given year runs early or late by a week or two, and the declared start and end are announced during the season rather than fixed in advance.
| Region | Typical start | Typical end |
|---|---|---|
| Okinawa | Early May | Late June |
| Kyushu and Shikoku | Late May / early June | Mid July |
| Kansai — Kyoto, Osaka | Early June | Mid to late July |
| Kanto — Tokyo | Early June | Mid to late July |
| Tohoku | Mid June | Late July |
| Hokkaido | No defined rainy season | — |
Hokkaido is the outlier worth planning around. The front usually weakens before it gets that far north, which is why June and early July are a good time to be on the northern island while the rest of the country is grey.
What tsuyu is actually like
The name translates as plum rain and the reality is closer to a long humid spell than a monsoon. Rain falls on roughly half the days, often as extended drizzle rather than downpours, and the sun appears between systems. Temperatures sit in the low to mid twenties Celsius with humidity high enough that the air feels heavier than the thermometer suggests.
Almost nothing closes. Trains run, museums open, restaurants are quieter than usual. The things that suffer are long mountain views, hiking on exposed trails, and photographs of anything you travelled a long way to photograph.
What tsuyu is good for
Gardens are at their best. Moss, hydrangeas and temple gardens in Kyoto and Kamakura are photographed in June for a reason. Indoor Japan — museums, department store food halls, covered shopping streets, onsen towns — is unaffected, and it is all noticeably less crowded.
Typhoon season
Storms form in the Pacific from around May and can approach Japan through October. August produces the most storms by count; September is the month when tracks most often bring them across the country. Two to three typhoons make landfall or pass close in a typical peak season.
| Region | Exposure |
|---|---|
| Okinawa | Highest — directly in the track |
| Kyushu and Shikoku | High |
| Kansai and Kanto | Moderate, several near passes a year |
| Tohoku | Lower, weakening systems |
| Hokkaido | Lowest |
The practical effect is disruption rather than danger, provided you are indoors. Japan handles storms methodically: railway operators announce planned suspensions the day before, airlines cancel in blocks, and shops shut early. A typhoon typically costs a traveller one lost day, occasionally two.
Planned suspension is the term to watch for
Japanese railways announce service suspensions in advance rather than stopping trains mid-journey. If a Shinkansen line publishes a planned suspension for tomorrow, move your travel today. Waiting to see what happens is how people end up stranded a prefecture away from their hotel booking.
Travelling through either season
- Check the national weather agency forecast daily during August and September. It publishes storm tracks and warning levels in English.
- Keep the itinerary loose in the peak weeks. Non-refundable bookings on consecutive days in different cities are the thing a typhoon punishes.
- Do not fly on the day of a forecast landfall if you can move it. Airlines usually waive change fees when they issue a weather advisory, and doing it early gets you a seat.
- A cheap plastic umbrella is sold in every convenience store for a few hundred yen. Do not pack a bulky one.
- Shoes that cope with wet matter more than a raincoat, and they intersect with how often you take them off indoors.
The trade against crowds and price
June is one of the least crowded months of the Japanese year, sitting between the Golden Week peak and the domestic summer holidays. Accommodation is cheaper, popular sites are walkable, and restaurant reservations that are impossible in April open up.
Crowding through tsuyu, on a five-point scale:
August is the opposite trade. The weather risk is higher and it is also peak domestic travel, because the Obon period falls in mid-month and moves the country at once. Bad weather and full trains together is the worst combination in the calendar.
For the full month-by-month picture, including temperature, rainfall, price and crowding scored against each other, see the best time to visit Japan.
Sources
- Japan Meteorological Agency — average start and end dates of the baiu season by region, and tropical cyclone statistics by month.
- Japan Meteorological Agency — weather warnings, advisories and tropical cyclone track forecasts.
- Published planned-suspension policies of the major Japanese railway operators.
Data checked: 2026-09-27
