According to the Japan Meteorological Agency, the rainy season ended in western Japan on June 27th.
This is the earliest end of the rainy season in the history of Japanese meteorological observations.
It looks like the hot summer will be long in Japan this year. Please be careful.
------------*-----------*-----------
The 2025 rainy season in Japan is expected to feature a “shorter duration,” “average to above-average rainfall,” and “increased risk of heavy rain disasters during peak periods.” Below, you’ll find a detailed explanation including the expected timing of the rainy season’s start and end in each region, weather trends, and points to watch.
Regional Overview: Start and End of the Rainy Season
Okinawa & Amami
Start: Late May (later than usual)
End: Mid-June (earlier than usual)
Duration: More than 10 days shorter than average
Rainfall: Average or less than average
Southern Kyushu
Start: Around May 30 (about average)
End: Mid-July (slightly earlier than usual)
Rainfall: Average or above average
Northern Kyushu, Shikoku, Chugoku, Kinki, Tokai, Kanto-Koshin
Start: Early June (about average)
Specifically, around June 4–7
End: Mid-July (about average or slightly earlier)
Rainfall: Average or above average
Hokuriku & Southern Tohoku
Start: Mid-June (about average or slightly later)
End: Mid-July (earlier than usual)
Rainfall: Average or above average
Northern Tohoku
Start: Mid-June (about average)
End: Late July (earlier than usual)
Rainfall: Average or above average
Characteristics of the 2025 Rainy Season
General Trends
Overall, the rainy season will be shorter than usual, especially in Okinawa and Amami, where it may be more than 10 days shorter than average.
The rainy season will progress from south to north, with both the start and end dates moving up the archipelago.
Compared to last year (2024), the rainy season will start earlier in many regions. In 2024, the start was generally late, but in 2025, it is expected to be average or slightly early.
Rainfall and Heavy Rain Risks
Okinawa & Amami: Rainfall will be average or below average. However, from early to mid-June, the rainy front may become active, bringing heavy rain at times.
Southern Kyushu to Northern Tohoku: Rainfall will be average or above average. Particularly from late June to early July, the Pacific high-pressure system will strengthen, activating the rainy front and increasing the risk of heavy rain and disasters in western and eastern Japan, as well as Hokuriku and Tohoku.
Meteorological Background
In 2025, the influence of the La Niña phenomenon is weakening, and sea surface temperatures in the western tropical Pacific remain high. As a result, the jet stream tends to flow further north, and the Pacific high-pressure system is expected to expand strongly.
In June, the Pacific high will be strong, causing the rainy front to linger around Kyushu and the southern coast of Honshu.
In July, the Pacific high will extend further north, pushing the rainy front up to the Sea of Japan and Tohoku regions.
Regional Rainfall Peaks and Precautions
| Region | Peak Rainfall Period | Rainfall Trend | Points of Caution |
|---|---|---|---|
| Okinawa & Amami | Early to mid-June | Avg. or below avg. | Watch for heavy rain, river flooding, and landslides |
| Kyushu–Kanto-Koshin | Late June | Avg. or above avg. | Heavy rain, landslides, urban flooding |
| Hokuriku & Tohoku | Early July | Avg. or above avg. | Heavy rain, river flooding, landslides |
From late June to early July, warm, moist air will flow into the rainy front, activating it and increasing the risk of heavy rain, especially in western and eastern Japan, Hokuriku, and Tohoku.
Be prepared for river flooding, house inundation, and landslides.
2025 Regional Rainy Season Forecast Summary
| Region | Start (Forecast) | End (Forecast) | Duration Trend | Rainfall Trend |
|---|---|---|---|---|
| Okinawa | Late May | Mid-June | Shorter | Avg. to below avg. |
| Amami | Late May | Late June | Shorter | Avg. to below avg. |
| Southern Kyushu | Around May 30 | Mid-July | Average | Avg. to above avg. |
| Northern Kyushu | Around June 4 | Mid-July | Average | Avg. to above avg. |
| Shikoku | Around June 5 | Mid-July | Average | Avg. to above avg. |
| Chugoku | Around June 6 | Mid-July | Average | Avg. to above avg. |
| Kinki | Around June 6 | Mid-July | Average | Avg. to above avg. |
| Tokai | Around June 6 | Mid-July | Average | Avg. to above avg. |
| Kanto-Koshin | Around June 7 | Mid-July | Average | Avg. to above avg. |
| Hokuriku | Around June 11 | Mid-July | Average | Avg. to above avg. |
| Southern Tohoku | Around June 12 | Mid-July | Average | Avg. to above avg. |
| Northern Tohoku | Around June 15 | Late July | Average | Avg. to above avg. |
| *Dates are estimates; please check the latest updates from the Japan Meteorological Agency or weather services. |
Summary and Preparation
In 2025, the rainy season is expected to start late and end early in Okinawa and Amami, while other regions will see average timing.
The rainy season will be shorter overall, but total rainfall will be average to above average, with a heightened risk of localized heavy rain and disasters, especially from late June to early July.
Prepare early for river flooding, landslides, and urban flooding, and pay close attention to the latest weather information.
"This year, rainfall during the rainy season is expected to be average or below average in Okinawa and Amami, and average or above average from southern Kyushu to northern Tohoku. There is a heightened risk of heavy rain disasters from late June to early July
Tips for Rainy Season Preparation
Confirm evacuation routes and shelters
Prepare emergency supplies and disaster kits
Clean gutters and drainage
Check the latest weather updates frequently
The 2025 rainy season is expected to be “short but intense,” with a higher risk of heavy rain and disasters during peak periods. Early preparation and staying informed are more important than ever this year.
