Summary of weather and temperature (August 23rd to August 29th) Record heavy rain in Hokuriku Level 5 heavy rain special warning announced in Ishikawa-Toyama

2026/09/01 11:50

This is a summary of the weather and temperature from August 23rd to August 29th, 2026.

[About this period's weather]
#Characteristics of pressure distribution
On the 23rd, Typhoon No. 18 moved west-northwest near Ogasawara, and Typhoon No. 19 almost stopped in the Gulf of Tonkin. Typhoon No. 20 moved southwest through the Taiwan Strait. On the 24th, extremely strong typhoon No. 18 moved westward from the south of Japan. Additionally, Typhoon No. 21 formed east of the Philippines, and a cold front moved southward over Hokkaido. On the 25th, a strong typhoon No. 18 moved westward near the main island of Okinawa. A low pressure system accompanied by a front passed from the Sea of Japan to the southern part of Hokkaido. On the 26th, the autumn rain front stalled from the Sea of Japan to the Tohoku region, and powerful Typhoon No. 18 passed near Okinawa and moved westward through the East China Sea. On the 27th, an autumn rain front extended from the Sea of Japan to the Tohoku region, and powerful Typhoon No. 18 moved westward through the East China Sea. On the 28th, a low-pressure system with cold air in the sky moved northeast from the vicinity of Hokkaido to the waters near the Chishima Islands, and an autumn rain front extended to the vicinity of western and eastern Japan. In addition, Typhoon No. 18 moved westward through the East China Sea and made landfall in central China. On the 29th, an autumn rain front extended from the Sea of Japan to eastern Japan. Additionally, Typhoon No. 18 turned into a tropical cyclone in central China.
#Precipitation
On the 23rd, heavy rain occurred in the Sakishima Islands due to Typhoon No. 20. Daily precipitation on Yonaguni Island is 118mm. On the 24th, locally heavy rain occurred from Tohoku to Kinki. Tomi City, Nagano Prefecture 40.5mm/h. On the 25th, heavy rain fell in southern Hokkaido due to warm and humid air. At Hobetsu in Mukawa Town, it reached 61mm/h, the highest in recorded history. In addition, a linear rain belt formed in the Amami region due to Typhoon No. 18. On the 26th, it rained in Okinawa/Amami due to Typhoon No. 18. Daily precipitation exceeds 240 mm in Amagi, Kagoshima Prefecture. On the 27th, extremely heavy rain occurred from Hokkaido to Tohoku in front of a low-pressure system in the Sea of Japan. Record-breaking heavy rain of 100mm/h in a short period of time in Mashike Town, Hokkaido. Additionally, due to the effects of the autumn rain front, a Level 5 heavy rain special warning was announced in Ishikawa and Toyama prefectures. The heaviest rainfall in recorded history was 300 mm in Himi City, Toyama Prefecture, and 288 mm in Hakui City, Ishikawa Prefecture. On the 28th, a linear precipitation band occurred in Hokkaido. 70.5mm/h in Nemuro City, Hokkaido. Also, due to the influence of the autumn rain front, there was extremely heavy rain on the Sea of Japan side. Himi City, Toyama Prefecture 75mm/h. On the 29th, extremely heavy rain was observed around Hokuriku due to the influence of the autumn rain front. 64.0mm/h was observed in Miyama, Fukui City, Fukui Prefecture.
#Temperature
On the 23rd, western Japan was covered with a tall high-pressure system, causing clear skies and rising temperatures. On the 24th, it was sunny from western Japan to eastern Japan, and temperatures rose with warm air reaching 18 C or higher at an altitude of around 1,500 meters. 39.5c observed in Otsu City, Shiga Prefecture. At three other locations, the temperature exceeded 39 degrees Celsius, dangerously hot and exceeding body temperature. On the 25th, a high pressure area existed from western Japan to eastern Japan. The downflow of Typhoon No. 18 strengthened the power of the high pressure system, and there were four locations where the temperature exceeded 39 degrees Celsius, including 39.1 degrees Celsius in Yatsushiro City, Kumamoto Prefecture. On the 26th, western and eastern Japan were covered in a Pacific anticyclone, resulting in a severe lingering heat. Extremely hot days of 40c or higher were observed at two locations in Fukuoka Prefecture. Extremely hot days also affected 246 locations. On the 27th, a Pacific high-pressure system extended into western Japan, causing clear skies and rising temperatures in western Japan, resulting in extremely hot days in some places. On the 28th, there were some places in Kyushu and Shikoku that were covered in high pressure and the sun hit, making it an extremely hot day. On the 29th, the severe summer heat continued in western Japan. In the Kanto region, which was north of the front, the weather was cloudy and rainy, and the temperature did not rise during the day, making it moderately hot.



# Weather summary for this period (August 23rd to August 29th)
Average temperatures were above normal across the country, and in particular in northern Kyushu and the Seto Inland Sea in western Japan, there were many days when the sky was covered by a tall high-pressure system with warm air, resulting in record high temperatures of more than 3 degrees above normal. On the other hand, in Hokkaido, temperatures were below normal in the northern part of the island due to the influence of cool air from the Sea of Okhotsk High.
Due to the influence of humid air, the autumn rain front that extends from the Sea of Japan to the vicinity of northern Japan became more active, with many areas centered on the Sea of Japan and Hokkaido exceeding normal levels, and some areas around Hokuriku exceeding 400%. On the other hand, on the Pacific side, which was far from the front, many places were covered by high pressure and there were many sunny days that made it difficult for heavy rain to occur, resulting in a tendency for rainfall to be much lower than normal in many areas. On the other hand, the Nansei Islands received much more rainfall than normal due to Typhoon No. 18.
Sunshine hours were above normal in many locations as western Japan was covered in high pressure and had many sunny days. In eastern and northern Japan, many places were cloudy and rainy due to the influence of humid air and fronts, and temperatures were at or below normal. In the Nansei Islands, there were many cloudy and rainy days due to Typhoon No. 18 and humid air, and the weather was well below normal.

Today, September 1st (Tuesday), it is dangerously hot in western Japan, and a low pressure system has formed in the Sea of Japan.

2026/09/01 11:09

Today, the 1st (Tuesday), the area around Japan will be covered in high pressure, and strong sunlight will reach western Japan.
Temperatures are expected to reach 38 degrees Celsius in Toyooka City, Hyogo Prefecture, Tottori City, Tottori Prefecture, and Yonago City, Tottori Prefecture, and the rest of western Japan is also at risk of dangerously hot temperatures exceeding body temperature. Please take all possible measures to prevent heat stroke.



Meanwhile, a low pressure system that will form on a front near central China is expected to continue to develop over the 2nd, moving northeast and reaching west of Hokkaido.



In Hokkaido, the rain is expected to become heavier mainly in the southern part of Hokkaido, and the rain is expected to spread further on the 2nd (Wednesday). Please check the latest information frequently.



Also, as moist air flows toward low pressure, atmospheric conditions will become unstable in the afternoon over a wide area from northern to western Japan. Be careful of sudden thunderstorms and strong rain, and be sure to check the rain cloud radar when you go out.

September starts with severe lingering heat mainly in western Japan, cloudy and rainy in northern Japan

2026/09/01 06:58

Today, September 1st (Tuesday), the lingering heat continues to be severe, especially in western Japan, and many places are likely to experience extreme heat with temperatures exceeding 35c. On the other hand, clouds tend to spread over Hokkaido and Tohoku, and rain will spread over the area in the afternoon. In areas that have experienced heavy rain, such as Hokuriku, please be careful of landslides even if there is a little rain.



Today's 1st (Tuesday), the start of September, will be sunny during the day and a harsh lingering heat will continue from Kyushu to the Tokai and Hokuriku regions due to the influence of the Pacific high pressure system that extends near Honshu.





The maximum temperature will rise above 35c, with temperatures in Kanazawa, Osaka, Nagasaki at 35c, Fukuoka at 36c, Hiroshima, Matsue at 37c, Kyoto and Nara at 38c, and many places will experience extremely hot days. A heatstroke warning alert has been announced in 16 prefectures, mainly in western Japan, and the risk of heatstroke will continue into September, so please continue to take precautions against the heat, such as by frequently drinking water and salt and using appropriate air conditioning.

Hokkaido and Tohoku are prone to clouds spreading due to the influence of fronts and low pressure systems, and it is likely that rain will gradually increase in many places. Please note that there is a possibility of heavy rain in Hokkaido at night.
Although there will be periods of sunshine in the Kanto region, clouds will likely spread. There is a chance of showers mainly in the north. Hokuriku will also have periods of sunshine, but the atmospheric conditions will become unstable in the afternoon, leading to heavy rain in some places.

Although the sun will shine during the day from Kinki to Kyushu, the atmospheric conditions will be unstable in the afternoon, and localized areas are likely to see heavy rain accompanied by thunder.

Tomorrow, September 1st (Tuesday), it is dangerously hot in western Japan, and a low pressure system has formed in the Sea of Japan.

2026/08/31 15:56

Tomorrow, the 1st (Tuesday), the area around Japan will be covered in high pressure, and strong sunlight will reach western Japan.
Temperatures are expected to reach 38c in places such as Toyooka in Hyogo Prefecture, Maizuru in Kyoto Prefecture, and Kurume in Fukuoka Prefecture, and the rest of western Japan is also at risk of dangerously hot temperatures exceeding body temperature. Please take all possible measures to prevent heat stroke.



Meanwhile, a low pressure system that will form on a front near central China is expected to continue to develop over the 2nd, moving northeast and reaching west of Hokkaido.





In Hokkaido, the rain is expected to become heavier mainly in the southern part of Hokkaido, and the rain is expected to spread further on the 2nd (Wednesday). Please check the latest information frequently.

Weather for the week: From now on, watch out for the autumn rain front and typhoon trends. There is a risk of warning-level heavy rain due to the typhoon + autumn rain front.

2026/08/31 14:10

From now on, the weather is likely to change dramatically depending on the autumn rain front and the movement of a tropical cyclone located south of Japan as of noon today, Monday, the 31st (expected to become a typhoon within the next 24 hours).
In particular, depending on the autumn rain front and typhoon trends, there is a possibility of warning-level heavy rain.



Tomorrow, the 1st (Tuesday), the first day of September, will have a similar atmospheric pressure distribution as today, the 31st (Monday). The lingering heat is severe in western Japan, which is covered by high pressure, so please be careful of heatstroke. Inland areas will experience localized rain and thunderstorms in the afternoon.
In northern Japan, the weather will gradually go downhill due to the effects of low pressure and fronts, and it will rain on the 2nd over a wide area of Hokkaido and northern Tohoku. In Hokkaido in particular, there is a possibility of warning-level heavy rain in southern and central Hokkaido, so please pay close attention to future weather information.



Also, the tropical cyclone moving south of Japan is expected to become a new typhoon by tomorrow 1st (Tuesday). Although the current forecast (as of noon on the 31st) is that there will be no strong winds, caution is needed as the moist air around the typhoon may activate the autumn rain front and cause heavy rain over a wide area.

On the 3rd (Thursday), rain is expected to occur over a wide area around Honshu due to the influence of the autumn rain front. In particular, the Hokuriku region, which was hit with record-breaking heavy rain that reached special warning levels last week, is at risk of experiencing heavy rain again.
On the 4th (Friday), as the autumn rain front moves southward, the area of rain is expected to shift from western Japan to the Pacific side of eastern Japan. The warm, humid air from the typhoon increases the activity of the autumn rain front, which can lead to increased rainfall and heavy rainfall even in areas far away from the typhoon.
Please be careful about the occurrence of heavy rain disasters such as flooding of low-lying land, rising river waters, and landslides, and be sure to check the latest weather information that will be updated in the future.




Until around the 2nd and 3rd, the high pressure system south of Japan will be strong in western and eastern Japan, and there will be some places where the lingering heat will be severe. Around the 2nd, the effect of cool easterly winds from the high pressure system on the Sea of Okhotsk side will weaken in the Tohoku Pacific side and Kanto region, and the heat is likely to return. From around the 3rd to 4th, the autumn rain front will move southward over Honshu, and the heat is expected to subside over a wide area from western to eastern Japan. However, the warm and humid air from typhoons tends to enter the area, so even if it's not extremely hot, it will still feel humid.

There will be many rainy days in Okinawa from now on. Depending on the path and strength of the typhoon, there is a risk of severe weather, so please be careful.

Two tropical cyclones are expected to become typhoons within the next 24 hours. Pay attention to future typhoon information.

2026/08/31 12:10

Today, the 31st (Monday), it was announced that two tropical cyclones are expected to develop into typhoons within 24 hours.

The first one is Tropical Cyclone A, which is located in South China as of 9am. This tropical cyclone was formerly Typhoon No. 18 (Soudel), and is expected to change its course eastward, head out over the South China Sea, and then develop into a typhoon again.
If it becomes a typhoon again, the original number will be used and it will be called Typhoon No. 18 again.

In this way, so-called "revival typhoons," which once transform from a typhoon to a tropical cyclone and then re-emerge as a typhoon, are said to occur only a few times a year or once every few years, making them rare. A recent example is Typhoon No. 8 (Komei) in July 2025, when a "revival typhoon" approached Okinawa and brought heavy rain.



This time, Tropical Cyclone A is expected to move eastward in the South China Sea and approach near Taiwan before becoming a tropical cyclone again.
Currently, it is not expected that there will be any major impact in the area around Japan, but please pay close attention to future information.

One more thing: Tropical Cyclone B, which will become a typhoon within the next 24 hours, is heading north over the southern seas of Japan. If it develops into a typhoon, it will be called Typhoon No. 24.
Tropical Cyclone B is expected to remain stationary in the south of Japan and become a typhoon by tomorrow 1st (Tuesday). Immediately after it becomes a typhoon, it is expected to move slowly, but after that it is expected to accelerate northward and approach Okinawa around the 3rd (Thursday).
Regarding the course from Friday the 4th, the range of the forecast circle is large, and the predicted course has a wide range. However, we cannot deny the possibility that it may approach Honshu after the 4th (Friday), so caution is required.

In addition, from the 4th (Friday) onward, the autumn rain front will move southward, and the moist air from the typhoon will activate the front, causing heavy rain mainly in areas on the Pacific side of western and eastern Japan. Please pay attention to the latest typhoon information that will be updated in the future.




#Typhoons in 2026 (as of August 31)
21 typhoons have already occurred this year, 2026.

This year, 2026, typhoons are occurring at a faster than normal pace. The average number of typhoons in August is 5.7, but this August there have already been 8 typhoons. If typhoon No. 24 occurs by today, the 31st (Monday), it will be the 9th typhoon to occur this month.

August and September are times when, compared to previous years, the number of typhoons occurring, approaching, and making landfall increases. Especially at this time of year, warm, humid air from the typhoon flows toward the autumn rain front, which can cause heavy rain even in areas far away from the typhoon on the Pacific side.

Please pay attention to the latest typhoon information that will be updated in the future and prepare as much as possible for typhoons.

The lingering heat continues to be severe from the Tokai region to the west, so be careful of heatstroke

2026/08/31 06:48

Today, the 31st, will be the last day of August, and high pressure will continue to cover western and eastern Japan, allowing sunlight to reach a wide area from the morning. Continuing from the previous day, the weather is expected to be sunny from the Tokai region to western Japan, with temperatures rising during the day, leading to extremely hot days with maximum temperatures of 35 C or higher and a severe lingering heat.
Today's highest temperature is expected to be in Nara, reaching 38 degrees Celsius, a dangerously hot temperature exceeding body temperature. In other regions, the heat can be as hot as body temperature, so you need to be careful about heat stroke.

On the other hand, the temperature in northern Japan does not rise much, making it a relatively pleasant experience.
In the Kanto region, clouds will spread and there will be no places where it will be extremely hot, but it will be a hot and humid day. It would be a good idea to choose clothes that are breathable.

The predicted maximum temperature in each region is Sapporo 24c, Sendai 26c, Tokyo 29c, Kanazawa 34c, Nagoya 36c, Osaka 36c, Kochi 34c, and Fukuoka 35c.



The Ministry of the Environment and the Japan Meteorological Agency have issued heatstroke warning alerts from western Japan to the Tokai region, covering 26 prefectures.

#Area covered by heat stroke warning alert
Shizuoka, Aichi, Mie, Fukui, Shiga, Kyoto, Osaka, Hyogo, Nara, Wakayama, Okayama, Hiroshima, Shimane, Tottori, Tokushima, Kagawa, Ehime, Kochi, Yamaguchi, Fukuoka , Oita Prefecture, Nagasaki Prefecture, Saga Prefecture, Kumamoto Prefecture, Miyazaki Prefecture, Kagoshima (excluding the Amami region)

In areas where a heatstroke warning has been issued, there is a risk of damage to human health due to heatstroke due to extremely high temperatures.
Please refrain from activities during hot hours as much as possible, and be conscious of taking frequent breaks and replenishing hydration and salt intake.
Also, try to stay indoors in a cool environment by using an air conditioner, and take precautions against heatstroke indoors.

Weather for today, the 31st (Monday): Sunny mainly in western Japan, with clouds predominant in northern Japan and the Kanto region

2026/08/31 06:16

Frontal activity is expected to weaken on Monday, August 31st, the last day of August. The sky is likely to be cloudy in northern Japan. On the other hand, from the Tokai region to the west, it is expected to be sunny with strong sunlight.



The sky in northern Japan is prone to clouds due to the influence of humid air. It will be a sunny day in Hokkaido, but there is a chance of showers in Tohoku. It will be safe to have a folding umbrella when you go out.

Although there are some sunny days in the Kanto region, it is a cloudy day. Please be careful of sudden thunderstorms especially along the mountains.

Tokai, Hokuriku, and western Japan are sunny and the sun shines. The lingering heat will continue to be severe during the day, and many places will experience extreme heat. Please take proper measures to prevent heat stroke. In the afternoon, there are places where there will be sudden thunderstorms mainly along the mountains. Please also pay attention to changes in the sky.

In Okinawa, there are many places where the sun reaches at first, but the weather goes downhill towards night. It will start to rain at night, so if you will be returning late, please bring rain gear.

Weather forecast for tomorrow 31st (Monday): The last day of August will be extremely hot. Inland areas should be careful of sudden changes in weather from the afternoon.

2026/08/30 18:40

Tomorrow, the 31st (Monday), the activity of the autumn rain front will weaken near Honshu, and a wide area of western and eastern Japan is expected to be covered in high pressure.



The weather for tomorrow, the 31st (Thursday), will be sunny in many places, although there will be a lot of clouds during the day. However, the high pressure system in the south of Japan is strong, and many places are expected to experience even more intense heat than the previous day, the 30th (Sunday).



The expected maximum temperature is 38c in Nagoya, Gifu, and Nara, and 37c in Kyoto, Okayama, Saga, and Kumamoto. It is expected that there will be places, mainly in western Japan, where the heat will be dangerously high, exceeding body temperature.
Even in eastern and northern Japan, many places are expected to be hotter than the previous day on the 30th, so it's likely to be hot and humid. In Hokuriku, Fukui, which experienced record heavy rain on the 30th, is forecast to experience a hot day of 35 degrees Celsius.
To avoid heat stroke, please continue to prevent heat stroke by hydrating frequently, supplementing with salt, and taking adequate breaks.



Even in sunny areas, rain clouds are likely to develop locally in the afternoon, mainly inland and along mountains, due to rising temperatures and moist air. Pay attention to changes in the sky, such as sudden rain or thunderstorms.

In Okinawa, even if it starts out sunny, clouds will gradually spread due to the influence of the moist air from the tropical cyclone. The weather will turn downhill towards the end of the night, with rain expected in many places. In addition, waves are expected to gradually increase in coastal areas, so please be careful of high waves accompanied by strong winds and swells.

Autumn rain front stagnates near Honshu; record-breaking heavy rain never experienced in Fukui Prefecture

2026/08/30 11:51

Today, the 30th (Sunday), an autumn rain front is stationary near Honshu from the Sea of Japan to the sea east of Japan, and a low pressure system is moving through the Sea of Japan.
Very warm and humid air is flowing towards the front and low pressure system, making the atmospheric conditions extremely unstable.

In the vicinity of Hokuriku, rain clouds that repeatedly developed continued to pass yesterday on the 29th, causing heavy rain, and today, on the 30th (Sunday), a Level 5 heavy rain special warning was announced for Fukui City, Katsuyama City, and Ono City in Fukui Prefecture. (*At 11:40 a.m., the special warning was switched to a warning.)
Some areas in Fukui Prefecture are experiencing heavy rain that has never been experienced before. The 24-hour rainfall up to 10 a.m. today, the 30th (Sunday), was 346.5 mm in Katsuyama City, Fukui Prefecture, 312.5 mm in Miyama, Fukui City, and 30.5 mm in Harue, Sakai City, all of which were record heavy rains that broke the highest values in the history of observation since statistics began.
In Katsuyama City, nearly 1.8 times the amount of rainfall in a normal August fell in just over a day.
In Fukui Prefecture, there are areas where serious disasters such as flooding and river flooding have already occurred, mainly in areas where special warnings have been issued. Please take extreme precautions against flooding of low-lying land, rising water levels and flooding of rivers.



In addition, there are areas in Fukui Prefecture where level 4 landslide warnings have been issued, mainly in the northern part of Reihoku, and the situation is such that landslides could occur at any time. Although the rain is expected to ease into the afternoon, the record-breaking heavy rain has loosened the ground, so please be on guard against landslides even with a little rain.





From now on, the front will remain in the Sea of Japan until tonight, and there will be areas where rain clouds that have developed mainly on the Sea of Japan side will flow into the area.
From mid-afternoon to evening, rain is expected to spread across areas along the Sea of Japan in the Tohoku region and within Niigata Prefecture, with heavy rain expected to be accompanied by thunder in some places in Niigata Prefecture.
In the Tokai region and western Japan, atmospheric conditions are expected to become unstable due to rising daytime temperatures and warm, humid air moving towards the front, leading to localized heavy rain accompanied by thunder.
Be careful of landslides, flooding of low-lying areas, and sudden rises in river water, and be careful of lightning strikes, tornadoes, and other strong gusts of wind.