Japan publishes the two numbers this question actually turns on, and neither of them is a “season.” The Japan National Tourism Organization publishes how many people arrived in each month, and the Japan Meteorological Agency publishes the average start and end of the rainy season for twelve separate regions. On the 2025 arrival figures, April and October were the two busiest months and February and September the two quietest — and March, the month people associate with cherry blossom, came seventh.
The published arrival figures rank the months for you
JNTO’s table of 2025 monthly totals is the only ranking here that does not depend on anyone’s opinion. It counts arrivals, not crowds at any one place, but it is the closest published proxy to how many other visitors are in the country in a given month.
| Rank | Month (2025) | Visitor arrivals |
|---|---|---|
| 1 | April | 3,909,128 |
| 2 | October | 3,896,524 |
| 3 | January | 3,781,629 |
| 4 | May | 3,693,587 |
| 5 | December | 3,617,700 |
| 6 | November | 3,518,000 |
| 7 | March | 3,497,755 |
| 8 | July | 3,437,118 |
| 9 | August | 3,428,406 |
| 10 | June | 3,377,985 |
| 11 | September | 3,267,228 |
| 12 | February | 3,258,491 |
Two things in that table are worth pausing on. The first is how narrow it is: April, the top month, exceeded February, the bottom month, by 650,637 arrivals, which is just under 20 percent. There is no month in which Japan empties out.
The second is March. Cherry blossom is the reason March is talked about, but on these figures March sat in seventh place, below December and November. April, the month above it, is where the arrivals actually concentrate — and April also contains the run-up to Japan’s spring holiday block, which we cover separately in our piece on Golden Week.
One detail about the table itself: the November and December entries are printed as rounded figures, and the twelve months as printed add to 42,683,551 against a published annual total of 42,683,600, a difference of 49. Read the monthly figures as the shape of the year rather than as a settled census.
The rainy season is twelve regional dates, and Hokkaido is not one of them
There is no national rainy season in Japanese official data. JMA issues baiu onset and withdrawal dates region by region, and it publishes a long-run average date for each. The list covers twelve regions, and Hokkaido is not among them.
| Region | Average onset | Average end |
|---|---|---|
| Okinawa | 10 May | 21 June |
| Amami | 12 May | 29 June |
| Southern Kyushu | 30 May | 15 July |
| Northern Kyushu | 4 June | 19 July |
| Shikoku | 5 June | 17 July |
| Chugoku | 6 June | 19 July |
| Kinki | 6 June | 19 July |
| Tokai | 6 June | 19 July |
| Kanto-Koshin | 7 June | 19 July |
| Hokuriku | 11 June | 23 July |
| Southern Tohoku | 12 June | 24 July |
| Northern Tohoku | 15 June | 28 July |
Read down the onset column and the practical point appears. Okinawa’s average onset is 10 May and Northern Tohoku’s is 15 June, thirty-six days apart. A trip that runs Okinawa first and Tohoku last in late May and early June can be inside the rainy season at the start and ahead of it at the end. Kinki, which includes Kyoto and Osaka, and Kanto-Koshin, which includes Tokyo, sit within one day of each other at 6 and 7 June, so Tokyo, Kyoto and Osaka behave as a single unit on this measure rather than three separate decisions.
Hokkaido’s absence from the list is a fact about the data, not a promise about the weather. JMA does not issue baiu dates for it.
September is worth a separate note, because it is the second-quietest month in the arrival table and sits after every region’s average withdrawal date. The obvious explanation would be typhoons, but the only cyclone timing JMA gives on its climate overview is that arrivals of tropical cyclones near Okinawa and Amami peak in August. That page does not carry a September figure, and it does not extend the statement to the main islands, so the arrival trough in September is not something these two sources explain between them.
The averages hide a window a month wide
An average date invites people to plan against it, which is where the trouble starts. For Kanto-Koshin, JMA’s record of past years gives an earliest onset of around 22 May, in 2025, and a latest of around 22 June, in 1967 and again in 2007. That is a window of one calendar month for a single region.
The end date moves as much. The earliest recorded withdrawal for the same region is around 28 June, in 2025, and the latest is around 4 August, in 1982 — a spread of thirty-seven days. JMA also notes that onset and withdrawal each occupy a transition period averaging about five days, which is why its dates are published as “around” a given day rather than on it.
So the average dates tell you what to expect and how far expectation can miss. Booking a mid-June trip on the strength of a 19 July average withdrawal is planning against a figure that has landed as much as twenty-one days earlier and sixteen days later than the average.
JMA describes the climate regionally before it describes it nationally
JMA’s own overview for visitors divides the year into four three-month blocks: December to February as winter, March to May as spring, June to August as summer, and September to November as autumn. What it says inside those blocks is mostly about where you are, not when.
- In winter, the Sea of Japan side receives heavy snowfall while the Pacific side gets sunny weather — the same months, opposite conditions, on two sides of one country.
- Inland areas of Hokkaido frequently record temperatures as low as −20°C.
- Okinawa and Amami have mild winters, which JMA attributes to their subtropical location.
- Western Japan in summer sometimes reaches 35°C or above.
- On the Pacific side of northern and eastern Japan, a cool easterly wind JMA calls Yamase brings cloudy and rainy conditions.
- The number of tropical cyclones approaching Okinawa and Amami peaks in August.
Those six points do more work than a national month-by-month table would. Kanazawa sits on the Sea of Japan side and Tokyo on the Pacific side, so on JMA’s own description the same winter month is a different proposition in each.
What the two datasets settle between them
Between them, JNTO and JMA settle three questions and leave one open.
They settle how the months rank by arrivals: April and October at the top, February and September at the bottom, and a gap between top and bottom of under 20 percent. They settle when rain is statistically likely and where: mid-June to mid-July covers the average baiu period for everywhere from Southern Kyushu to Northern Tohoku, while Okinawa is typically finished by 21 June. And they settle that the rainy season is a regional object, with Hokkaido outside the system entirely.
What they do not settle is which month suits a particular trip, because the two datasets point in different directions. February is the quietest month in the arrival figures and sits inside JMA’s winter block, with everything that implies on the Sea of Japan side; October is second-busiest and sits outside every region’s average baiu window. That trade is the actual decision, and it is yours rather than a dataset’s.
Sources Checked
Japan National Tourism Organization — 2025 monthly visitor arrivals table
Confirmed the monthly totals for 2025 used above: January 3,781,629; February 3,258,491; March 3,497,755; April 3,909,128; May 3,693,587; June 3,377,985; July 3,437,118; August 3,428,406; September 3,267,228; October 3,896,524; November 3,518,000; December 3,617,700; and the published annual total of 42,683,600.
https://www.jnto.go.jp/statistics/data/_files/20260121_1615-4.pdf
Japan Meteorological Agency — past rainy season onset and withdrawal dates
Confirmed that JMA issues baiu dates for twelve regions (Okinawa, Amami, Southern Kyushu, Northern Kyushu, Shikoku, Chugoku, Kinki, Tokai, Kanto-Koshin, Hokuriku, Southern Tohoku, Northern Tohoku), that Hokkaido is not among them, and that dates are confirmed after the season on the basis of observed weather, with the published date representing the middle of a transition period averaging about five days.
https://www.data.jma.go.jp/cpd/baiu/index.html
Japan Meteorological Agency — confirmed 2025 rainy season report, which prints the long-run average dates alongside the year’s dates
Confirmed the average onset and withdrawal dates for all twelve regions as tabulated above.
https://www.data.jma.go.jp/cpd/longfcst/seasonal/202508/tsuyu2025.pdf
Japan Meteorological Agency — past rainy season dates for the Kanto-Koshin region
Confirmed the region’s average onset of around 7 June and average withdrawal of around 19 July, the earliest recorded onset of around 22 May (2025) and latest of around 22 June (1967 and 2007), and the earliest recorded withdrawal of around 28 June (2025) and latest of around 4 August (1982).
https://www.data.jma.go.jp/cpd/baiu/kako_baiu09.html
Japan Meteorological Agency — overview of Japan’s climate
Confirmed the four three-month seasonal blocks; heavy snowfall on the Sea of Japan side against sunny weather on the Pacific side in winter; temperatures as low as −20°C frequently observed in inland Hokkaido; mild winters in Okinawa and Amami; summer temperatures of 35°C or above in western Japan; the Yamase easterly bringing cloudy and rainy conditions to the Pacific side of northern and eastern Japan; and the August peak in tropical cyclones approaching Okinawa and Amami.
https://www.data.jma.go.jp/cpd/longfcst/en/tourist_japan.html
Last updated: September 2026
