Record heavy rain in Niigata prefecture in a short period of time - about 100mm of rain per hour

2026/07/24 22:11

The Japan Meteorological Agency announced the first Niigata Prefecture Weather Disaster Prevention Bulletin (Heavy Rain in a Record Short Time) at 7:47 p.m. today, Friday, the 24th.
About 100 millimeters of heavy rain is thought to have fallen in the hour until 7:30 pm near Shibata City and Seigo Town, Niigata Prefecture.

The rainy season front is stationary near Niigata Prefecture, and rain is expected to continue into tomorrow, Saturday the 25th.
As warm, humid air flows towards the front, atmospheric conditions will become very unstable, and there will be some places with very heavy rain accompanied by thunder. If the rain clouds become stagnant or develop more than expected, there is a possibility that the area experiencing warning-level heavy rain may expand.
Please check the latest information and be prepared to take evacuation actions according to the alert level announced.



In Kaetsu, please be on high alert for landslides until dawn on Saturday the 25th.
In Niigata Prefecture, please be on alert for flooding of low-lying areas, rising water levels and flooding of rivers until late at night on the 25th (Saturday) tomorrow, and be alert for landslides into the 26th (Sunday). Also, be careful of strong wind gusts such as lightning and tornadoes.
If there are signs of a developing cumulonimbus cloud approaching, please take every precaution to ensure your safety, such as moving inside a building. There is also a risk of hail, so please be careful when managing crops and agricultural facilities.

#What is a weather disaster prevention bulletin (record-breaking heavy rain in a short period of time)

An announcement is made by the Japan Meteorological Agency when a short-term heavy rain that only occurs once every few years is observed or analyzed.

In order to make it known that the current rainfall is a rarely observed amount of rainfall that can lead to landslides, flooding damage, and flooding of small and medium-sized rivers in the area, the name of the observation point and city where the heavy rain was observed will be clearly stated if the rainfall standard is met and the "danger" (purple) status of the Kikikuru (risk distribution) has appeared during warning announcements regarding disasters during heavy rain.
Rainfall standards are generally determined for each prefecture and forecast area, with reference to the 1st or 2nd place in history for 1-hour rainfall.

#The areas where record-breaking heavy rain information was announced are...

It means that heavy rain is falling that can lead to landslides, inundation of low-lying land, and flooding.
Let's check where the risk of disaster occurrence is actually increasing using Kikikuru (risk distribution).

[Kanto] Is it safe to hold the Sumida River Fireworks Festival on the weekend with "the greatest risk of sudden weather changes" (Commentary: Weather forecaster Atsuko Miyake)

2026/07/24 14:33

From now until the weekend, the Kanto region will continue to experience unstable atmospheric conditions.
Even if the weather is sunny, be careful of sudden changes in the weather.




This is the forecast weather map from today (Friday) to the day after tomorrow (Sunday).
The front is expected to remain in a similar location for all three days.
A front is stationary from the Hokuriku region to the northern Kanto region, and
warm and humid air continues to flow toward this front from the south.

As a result, the atmosphere in the Kanto region remains unstable, making heavy rain and thunderstorms more likely.
Also, since the winds that move the rain clouds in the sky are weak,
there is a risk that it will continue to rain in similar places.
Please be careful about how it rains.



Now, let's take a look at the rain forecast.

After the evening, rain clouds may roll up from the mountains and may also flow into the plains.
It is likely that there will be heavy rain accompanied by thunder, or very heavy rain in some places.

In the Kanto region, 60mm of rain is expected per hour today.
This 60 mm is extremely heavy rain, falling like a waterfall.
In urban areas, if more than 50mm of rain falls per hour, the drainage will not be able to catch up and the roads will turn into rivers.
This is likely to be the way it rains.

A further 120 mm of rain is expected to fall by midday tomorrow (Saturday).
This 120mm of rain could fall all at once in just a few hours, so
Please be careful about landslides, rising and overflowing rivers, and flooding of low-lying areas.



When the date changes to tomorrow (Sat), the rain clouds are expected to disappear for a while.
Tomorrow morning, we may see some sunshine through the gaps in the clouds.

However, in the afternoon, rain clouds will start to form along the mountains.
Furthermore, rain clouds and thunderclouds may move into the plains from evening onwards.

There were also yellow and red signs in the southern Kanto region towards night.
There is a risk of heavy rain and very heavy rain depending on the location.

Please be careful of sudden changes in the weather tomorrow (Saturday) as well.



Saturday and Sunday weather.
There are almost no rain marks.
However, be careful of sudden changes in the weather both tomorrow and the day after.

Please think that there is a rain mark hidden behind this cloudy mark.
It's safe to bring rain gear when you go out.

And tomorrow (Saturday) there will be a fireworks festival on the Sumida River in Tokyo.
However, please don't be fooled by this cloudy mark and bring rain gear.


There is a risk of thunderstorms from tomorrow evening onwards.
If you hear thunder, try to move to a safe building.

And tomorrow (Saturday) it will continue to be hot and humid.
The temperature rises to 34c in Tokyo and 36c in Kumagaya and Maebashi. Please be careful of heat stroke.



Weekly forecast.
The sunny skies will return in the first half of next week.
The intense heat is likely to return in the second half.

Tokyo is also expected to experience another extremely hot day with temperatures exceeding 35c.
The intense heat is coming back, so
try to get in shape while the heat is still relatively strong in the first half of next week.

[Scorching heat in the west, heavy rain in the east] Extreme weather continues on the weekend (commentary: weather forecaster Atsuko Miyake)

2026/07/24 13:57

The weather and perceived temperature are likely to change significantly between the west and east this Saturday and Sunday.



This is what the clouds look like on the Himawari meteorological satellite.
The area west of the Tokai Sea is covered by high pressure and has many sunny days.
On the other hand, in areas north of the Kanto region, clouds are spreading due to fronts and moist air, and
there are places where it is raining.

The weather in the west and east is very different, and this difference is also reflected in the temperature.



Looking at the maximum temperature until noon, there are many areas west of the Tokai region that are marked in purple and have extremely hot days of 35c or higher.

On the other hand, in areas north of the Kanto region, the temperature is red, orange, and even yellow in some places, with temperatures around 20 to 30 degrees Celsius.


Looking at the maximum temperature until noon, it has exceeded 38 degrees in Gifu Prefecture and Nagoya City, making it an extremely hot day from the morning.

Until yesterday, the Tokai region has experienced three consecutive days of extremely hot weather with temperatures exceeding 40 degrees Celsius.
It continues to be dangerously hot and unbearably hot.
Please continue to be extremely careful about heat stroke.

And this situation in which weather and temperature trends vary greatly between the west and east is likely to continue into around the 26th (Sunday).



Let's take a look at the forecast weather map from today (Friday) to the 26th (Sunday).

The front is expected to stall from Hokuriku to northern Kanto and remain in a similar location.
The atmospheric conditions around this front are unstable, and there is a risk of heavy rain and thunderstorms in similar areas.
There is a risk that the amount of rain will increase, so please be careful about how it rains in areas north of Kanto.



Let's take a look at the rain cloud forecast.
A band of rain clouds is expected to form in the Tohoku region due to the front.
Also, in the Kanto region, rain clouds that have formed along the mountains are expected to gradually flow into the plains.

Even in places where it is not raining right now, you need to be careful about sudden changes in the weather after this.
Furthermore, there is a risk that rain will continue in similar areas from Niigata to the southern Tohoku region into the late evening.


Up to 80mm of rain is expected to fall in many places in the Tohoku region from now until the morning of Saturday the 25th.
Also, by noon tomorrow, 120 mm is expected in the Hokuriku and Kanto regions.
It is possible that this rain will fall all at once over a period of several hours.
Especially in the Kanto region, be careful of flooding in low-lying areas and rainwater flowing into underpasses.



The rain clouds in the Kanto region are expected to disappear in the morning of tomorrow (Saturday), but
in the Tohoku region, rain will continue in similar places.

In the afternoon, rain clouds will begin to appear again in the Kanto region.
There is a risk that rain clouds will develop again in central Tokyo after the evening of tomorrow (Saturday).

If you are going out tomorrow, please be careful of the latest rain cloud radar.
And there is a risk of heavy rain and thunderstorms in the southern Kanto region late into the evening.

Also, it will continue to rain in similar places in the Tohoku region, so even tomorrow (Saturday), please stay in a safe place on the second floor or above, away from cliffs.



Saturday and Sunday weather.
The region west of the Tokai Sea will continue to be sunny and extremely hot.
Nagoya tomorrow (Saturday) will also be as hot as 39 degrees Celsius, approaching an extremely hot day.
Please be careful of heat stroke.

There will be a lot of clouds in the Kanto and northern regions, and there is a risk of heavy rain and thunderstorms in the Tohoku and Hokuriku regions.
The Kanto region and Tokyo are marked as cloudy, but
Please be careful of sudden thunderstorms in the afternoon.
It's safe to bring rain gear when you go out.

Also, it will continue to be hot and humid in Tokyo, so please be careful of heatstroke.



Weekly forecast.
The rainy season front is expected to gradually move northward by the middle of next week.
It looks like sunny skies will return in the Hokuriku and Tohoku regions in the second half of next week.
The end of the rainy season seems to be near in this area.

The region west of the Tokai Sea is expected to continue experiencing extremely hot days of 35c or higher into next week.
It will be a hot day every day, so please take good care of your health.

Although there are few days in the Kanto region where the temperature reaches 35c for a while,
the extremely hot days are expected to return in the second half of next week.

[Atmospheric conditions are extremely unstable] Beware of sudden changes in the weather in the Kanto region - extremely heavy thunderstorms of 60mm per hour in Tokyo

2026/07/24 13:00

Today, the 24th (Friday), a front is extending from the Sea of Japan through Hokuriku to the east of Kanto.
In the Kanto-Koshin region, warm, humid air is moving in to the south of the front, and combined with the effects of rising temperatures during the day, atmospheric conditions are expected to become extremely unstable from the early afternoon of today, the 24th (Friday) until dawn on the 25th (Saturday).



In Kanto-Koshin, heavy rain accompanied by thunder will fall from late afternoon to late evening today, the 24th (Friday).
Especially in the Kanto region, there is a risk of extremely heavy rain of 60 mm per hour from evening to early night.
There will be heavy rain not only along the mountains and inland, but also in urban areas in the metropolitan area, including the 23 wards of Tokyo.
If rain clouds develop more than expected, or if developed rain clouds continue to cover the area, there is a risk that the area and period of warning-level heavy rain may expand.



Forecasted 1-hour precipitation for today, 24th (Friday) [in areas with the most]
Northern Kanto 60mm
Southern Kanto 60mm
Koshin 40mm

Forecasted precipitation for 24 hours until noon on the 25th (Saturday) the next day [in areas with high amounts]
Northern Kanto 120mm
Southern Kanto 120mm
Koshin 80mm

In the Kanto-Koshin region, please be on guard for flooding of low-lying areas, underpasses and underground facilities, rising water levels and flooding of rivers, and be careful of landslides this afternoon, Friday the 24th.

Today's 24th (Friday) weather: Heavy rain warning for southern Tohoku and Niigata

2026/07/24 07:05

The rainy season front is expected to move southward from the continent, through the Sea of Japan, and into the Kanto region. It is expected that the area from the Tokai Sea to the west will continue to be covered in high pressure.



The activity of the rainy season front will increase, and it will rain intermittently in southern Tohoku and Niigata. Please be careful as there is a risk of heavy rain locally. In northern Japan, there is less sunlight, so the temperature is less likely to rise, and there are many places that do not reach 30 degrees Celsius during the day.
As the rainy season front moves southward in the Kanto region, the weather is likely to gradually go downhill. In areas along the mountains, rain will begin as early as noon. Don't forget your umbrella as there will be widespread rain in the afternoon. The intense heat will subside a little as there will be less sunlight, but it will still feel hot and humid with temperatures exceeding 30 degrees Celsius and high humidity.
From the Tokai to the west, the temperature will be high and the sun will shine brightly in the morning, so it is likely to be dangerously hot. It will be as hot as yesterday, so please be extremely careful about heat stroke.



Today, July 24th, is Telework Day. Telework Day is a campaign carried out as part of work style reform, with July 24, the opening ceremony of the Tokyo Olympics and Paralympics, designated as "Telework Day." This campaign aims to alleviate traffic congestion, and the government and related organizations are working together to call for simultaneous implementation of telework.
We expect heavy rain in the southern Tohoku region and Kanto region, and heat that makes it dangerous to go outside from the Tokai region to the west, so we recommend teleworking from a weather perspective.

[Ocean Summary] Large ship erupts in the East China Sea due to Typhoon No. 9 (July 12-18, 2026)

2026/07/24 05:30

A large and strong typhoon No. 9 made landfall in central China. As a result of this, waves in the East China Sea reached a height of 6 meters and remained high until the 14th.
Below is a summary of the ocean (July 12-18, 2026)



#Barometric pressure distribution and waves
On the 12th, a large and strong typhoon No. 9 made landfall in China. As a result of this, waves in the East China Sea reached a height of 6m, and the waves remained high until the 14th, and high waves continued across the Pacific Ocean until the 13th. On the 13th, there was a trough in the atmospheric pressure near Hokkaido, with a low pressure system forming in the west of Hokkaido, and waves reaching 4 meters in height in the east of Hokkaido. On the 14th, a low pressure system became stationary to the east of Japan. There was a large pressure gradient between the area and the Aleutian high, and waves rose to the east of Hokkaido. On the 15th, a low pressure system moved northward over the Sea of Japan. Waves increased around the low pressure area. From the 17th to the 18th, the area was gently covered by high pressure, and the surrounding waters remained calm.



#Sea surface temperature
Sea surface temperatures in the Japanese waters are expanding in areas where they are higher than normal. Temperatures were significantly higher than normal mainly in the north, reaching a maximum of 4 C above normal. To the southeast of Hokkaido, areas of sea area where sea surface temperatures are significantly higher than normal have expanded. In the East China Sea and the waters around the Nansei Islands, waters lower than normal can now be seen. Sea areas slightly lower than normal continued off the coast of the southeastern Kanto region, and waters significantly higher than normal off the southeastern coast of Hokkaido shrank. In the waters near the Chishima Islands, the area of higher than normal waters expanded, and the Sea of Okhotsk remained slightly higher than normal.

[Typhoon information] Typhoon No. 12 occurs in the east of the Philippines

2026/07/24 05:17

At 3:00 on the 24th, a tropical cyclone became Typhoon No. 12 in the east of the Philippines.

As of 3:00 on the 24th
Center location: 17 55'N latitude, 125 05'E
Central pressure: 998hPa
Maximum wind speed near the center: 18m/s
Maximum instantaneous wind speed: 25m/s
Strong wind area of 15m/s or more: Entire area 330 km

Typhoon No. 12 is moving westward at a speed of approximately 35 kilometers per hour, accompanied by strong winds.



It is expected to reach the South China Sea at 3:00 on the 25th tomorrow, change course to the west-northwest, and land on the continent on the 26th.

As the typhoon approaches, people in the Nansei Islands need to be careful about the wind and waves.
Please pay attention to future information.

[Breaking News] A tropical cyclone has formed in the east of the Philippines. It is expected to develop into typhoon No. 12 on the night of the 24th.

2026/07/23 19:44

According to the Japan Meteorological Agency's announcement at 19:10, a new tropical cyclone has formed.

The tropical cyclone is moving west-northwest east of the Philippines.

Central location: 17 25'N, 127 50'E
Central pressure: 1000hPa
Maximum wind speed near the center: 15m/s
Maximum instantaneous wind speed: 23m/s

This tropical cyclone is expected to continue moving west-northwest and develop into a typhoon on the night of the
24th.
If it becomes a typhoon, it will be called Typhoon No.12.



After that, it will proceed to the South China Sea and is expected to make landfall in South China on the 26th.

Even if the typhoon itself is far away, the rain can suddenly intensify due to the influence of humid air, and the outside situation can change drastically
in a short period of time.

Please pay attention to the latest typhoon information.

[This year's record high of 40.9 degrees Celsius in Japan] Three consecutive days of extreme heat, but atmospheric instability "Beware of disaster-level heat and thunderstorms" (Commentary: Weather forecaster Atsuko Miyake)

2026/07/23 14:34

Please be on guard for the extreme heat and thunderstorms today.



Looking at the highest temperature until 2:20 pm today, the 23rd (Thursday),
Sakuma, Tenryu Ward, Hamamatsu City, Shizuoka Prefecture, reached 40.9c,
the highest temperature recorded in Japan this year.

In addition, Tajimi City, Gifu Prefecture, has experienced extremely hot days today with temperatures exceeding 40c for three consecutive days,
with dangerous and disaster-level heat in many places.
Please be extremely careful about heat stroke.

How long will this dangerous heat last



Looking at the maximum temperature in the weekly forecast,
we are forecast to experience extremely hot days of 35c or higher every day.
The temperature does not drop not only during the day but also at night, and the heat remains unbearable.
It may be a good idea to sleep with the air conditioner on so you can get a good night's sleep.



And in Nagoya, the temperature is expected to be 39c again tomorrow and the day after.
The extreme heat here continues.
Please be careful of heat stroke.


On the other hand, in the area north of Kanto, the extremely hot weather seems to be coming to an end for now.
This is because relatively cool air tends to flow around the edge of the Okhotsk High.

However, there are days in the Kanto region where the temperature rises to around 33-34 degrees Celsius, so
the heat and humidity continues.
Please continue to be careful of heat stroke.



Please use the air conditioner instead of putting up with the heat.
Also, try to walk in the shade and avoid direct sunlight as much as possible.
Also, try to eat a well-balanced diet and build your body to withstand the heat.




And from now on, you will also need to be careful of thunderstorms.

Looking at the forecast weather map for tomorrow (Friday) night,
there will be a high pressure system to the south, followed by high pressure from the north.

Warm, humid air flows in from the high pressure system in the south.
Also, relatively cool and humid air flows in from the high pressure system in the north.

These two different atmospheres are expected to collide, creating a front over the Hokuriku and Kanto regions.

The atmospheric conditions near this front are likely to become unstable, leading to thunderstorms in some places.



Now, let's take a look at the rain cloud forecast.
After the evening, rain clouds will develop over Kanto, Tohoku, and parts of Shikoku and Kyushu.
Rain clouds are flowing not only along the mountains but also into the plains,
especially in the Kanto region, where there is a risk of extremely heavy rain and thunderstorms even in central Tokyo.
Please be careful of flooding in low-lying areas and roads.


When the date changes, the rain clouds will disappear.



However, tomorrow (Friday), clouds associated with the front will cover the Tohoku region.
There is a risk of heavy rain and thunderstorms, especially in the afternoon, especially in the Tohoku region.
There are some areas where heavy rain will reach the warning level, so please be careful and be on guard against landslides.

In the afternoon, rain clouds will begin to flow into the Kanto region again.
Very heavy rain, possible heavy rain again.
Please be careful and be on guard for the rain tomorrow.

There is a risk that rain will continue in similar areas in the Tohoku region into the following day and into Saturday.
Please be careful about the rain as well.



shows the weather in various places.
The region from the Tokai region to the west will continue to experience intense heat until tomorrow.
Please be careful and cautious about heat stroke.
In addition, in the Tohoku region, Kanto region, and Hokuriku region, there is a risk of rain and thunderstorms even in places without the
rain symbol. Please be aware of sudden changes in the weather.

There is also a risk of heavy to very heavy rain. Please be careful of lightning and gusts of wind.



Weekly forecast.
From now on, rain will continue in the Hokuriku and Tohoku regions, where the rainy season has not yet ended. The rainy season front is expected to remain stationary.
Please be careful of heavy rains at the end of the rainy season.

On the other hand, the heat continues in areas west of the Kanto region, where the rainy season has ended.
The intense heat continues, especially in the areas west of the Tokai Sea, so please be careful of heat stroke.

Today, the 23rd (Thursday), is the 24th solar term ``Great Heat.'' Be careful of dangerous heat and sudden changes in weather from the afternoon.

2026/07/23 06:55

Today, the 23rd (Thursday), is the ``Great Heat'' of the 24 solar terms. It is said to be the hottest time of the year.



The area around Honshu is covered by a midsummer high-pressure system mainly in western and eastern Japan, and today it will be covered in warm air and the strong sun will beat down, making it extremely hot. The predicted maximum daytime temperature is expected to be 40 degrees Celsius in Kofu, Gifu, Nagoya, and Kyoto, 38 degrees Celsius in Osaka, and 37 degrees Celsius in Tokyo, making it dangerously hot and approaching body temperature. The temperature will not drop much at night, and it will be a tropical night in many places.

It is best to be extremely careful about heat stroke, drink plenty of water and salt, take adequate breaks, and refrain from strenuous exercise outdoors. Please use the air conditioner to stay in a cool environment day and night.



The front is stationary near the Sea of Japan. As of this morning, active rain clouds are hanging over Niigata Prefecture, and there are areas in Niigata Prefecture where a level 4 heavy rain danger warning has been issued. There is a risk of very heavy rain in the morning, so please be careful of heavy rain disasters.



In the afternoon, atmospheric conditions will become unstable in places around Honshu due to rising daytime temperatures and moist air. After noon, rain clouds and thunderclouds are likely to develop inland and along the mountains, and sudden heavy rain and thunderstorms are likely to occur in some places.
The probability of lightning strikes is particularly high in the Kanto region, and the rain clouds that have developed will spread to the plains, and it is likely that there will be extremely heavy rain of over 50mm per hour in some places. Please be careful of flooding of low-lying land, flooding of roads, and rising water of rivers. In addition, there is a risk of lightning strikes, tornadoes, strong wind gusts, and hail, so please be careful.
Pay close attention to changes in the sky, and if you see signs of sudden changes in the weather, such as seeing black clouds approaching or hearing thunder, please take precautions such as evacuating to a sturdy building.