Weather for tomorrow, the 16th (Sunday): The last day of Obon will be sunny in northern Japan. The sky will be dominated by clouds from eastern to western Japan.

2026/08/15 18:05

Tomorrow, the 16th (Sunday), the last day of Obon, will be covered in high pressure centered east of the Kuril Islands, and many places in northern Japan will be sunny. It looks like it will be a day with clouds spreading easily from eastern to western Japan.



In northern Japan, there will be many sunny places, especially on the Sea of Japan side. Clouds will spread out on the Pacific side, but the sky is likely to be sunny with periods of sunshine. Temperatures tend to rise on the Sea of Japan side due to humid easterly winds, and in some places the temperature will approach an extremely hot day. Please be careful of heat stroke.

The sky will likely be cloudy from eastern Japan to western Japan due to the influence of humid air. Although there are periods of sunshine in eastern Japan, you need to be careful of localized heavy rain. It's a day covered in thick clouds in western Japan. It would be safe to have a folding umbrella when going out. In addition, active rain clouds are likely to form in northern Kyushu. Please bring a large umbrella when going out.

Tomorrow, the 16th (Sun), the moon approaches Venus. Observe the "Evening Star"!

2026/08/15 17:39

After sunset on the 16th (Sunday), the slender Moon with an age of 3.4 will approach Venus in the western sky. Why not take a look at the bright, slender Moon and Venus

Venus orbits inward of the Earth in the solar system, so it can only be observed at dawn and sunset. For this reason, it is called the ``morning star'' and ``evening star.'' Today, the 15th (Saturday), its apparent position as seen from Earth will be the farthest from the Sun, at the greatest eastern elongation, and it will shine extremely brightly in the western sky. For this reason, it can be seen even when the sky is still bright.



The image shows the sky west of Tokyo 30 minutes after sunset on Sunday the 16th.
The thin moon and Venus shine as if they were close together. You can also see the first-magnitude star Spica in the constellation Virgo nearby.



Now, let's take a look at the weather distribution forecast around sunset on the 16th (Sunday) tomorrow.

Northern Japan is expected to be mostly sunny. This is a chance for stargazing.

Eastern Japan is likely to have areas where clouds tend to spread as moist air flows in around the edge of the high-pressure system near the Chishima Islands. You might also try aiming for gaps in the clouds.

Western Japan will experience rain in some places as warm, humid air flows in due to the low pressure system expected to move from the Yellow Sea to the Sea of Japan. Unfortunately, stargazing may be difficult.

Okinawa will probably have some clouds in some parts, but it will mostly be sunny.

Why not try stargazing on the last day of Obon vacation or as a memory of your summer vacation

Sea surface temperature drops due to Typhoon No. 13 [Ocean summary (August 2, 2026 - August 8, 2026)]

2026/08/15 17:15

Sea surface temperatures continued to be higher than normal on the Sea of Japan side, and on the Pacific side, where Typhoon No. 13 passed, were around normal or slightly lower than normal.

Below is a summary of the ocean (August 2, 2026 - August 8, 2026)



#Pressure distribution and waves
On the 2nd, Typhoon No. 13 moved west-northwest around Minamitorishima with very strong force, causing waves to rise around the typhoon. On the 3rd, Typhoon No. 13 moved westward near Ogasawara, causing waves to rise to around 2.5 meters in height on the Pacific side of eastern Japan. From the 4th to the 6th, Typhoon No. 13 moved westward from the south of Japan, causing wave heights to rise to 3 to 4 meters across a wide area on the Pacific side. On the 6th, the wave height was around 5m near the Nansei Islands. From the 7th to the 8th, large typhoon No. 13 approached and passed the main island of Okinawa while maintaining extremely strong strength. On the 7th, in Amami and Okinawa around the typhoon, the wave height was over 10 meters in some places, and it was very strong. On the 8th, waves were extremely strong in the Sakishima Islands with a height of around 9 meters.



#Sea surface temperature
In Japan's waters, areas with higher-than-normal temperatures have expanded compared to last week, with temperatures in the western region reaching a maximum of 4 C above normal. In the East China Sea and the waters near the Nansei Islands, the area of higher-than-normal waters shrank toward the latter half of the period, but it remained slightly higher than normal. Continuing from the previous week, the areas above normal in the Kanto and Sanriku offings and off the southeastern coast of Hokkaido continued to shrink, and the sea levels were at or slightly below normal. In the waters near the Kuril Islands and the Sea of Okhotsk, areas with higher-than-normal temperatures expanded toward the latter half of the period. In the waters around the Kuril Islands, the maximum temperature was 3 C above normal.

The sky continues to be unstable in the Kanto region. Be careful of sudden changes in the weather in the afternoon as well.

2026/08/15 12:24

The atmospheric conditions have been unstable in the Kanto region since yesterday, where moist air is flowing in around the edge of a high-pressure system centered near the Chishima Islands.

Kesa also started to fall intensified from dawn to dawn, with heavy rain of 39.0mm/h observed in Kisarazu City, Chiba Prefecture, and 32.0mm/h in Ome City, Tokyo.



Although the rain clouds have calmed down compared to Kesa, as of 12:00, rain clouds are still forming in some places in the Kanto region. Similar conditions will continue into the afternoon, with the weather expected to be sunny but changeable. It's safe to carry a folding umbrella when you go out.



Also, even a small amount of rain could cause landslides in areas where the ground has become loose due to previous rains, especially in Chiba Prefecture, which experienced heavy rain the other day. If you are involved in restoration work or live near a slope, please be careful and monitor the future movement of rain clouds.

Weekly weather: The Pacific high pressure system is gradually gaining strength, and the severe heat is likely to return gradually.

2026/08/15 07:26

From next week onwards, the Pacific high pressure system will gradually become more prominent near Japan. As a result, the severe heat will gradually return.





From tomorrow the 16th to the 17th, a low pressure system will approach from the west and move toward the Sea of Japan. Due to the influence of warm, humid air moving toward a low pressure system, rain and thunderstorms will occur in some places, mainly on the Sea of Japan side of western Japan, and localized rainfall will become stronger.
The Kii Peninsula and Shikoku are also expected to experience rain tomorrow, the 16th, due to the influence of moist air circulating around the edge of a high-pressure system. There is a possibility of heavy rain accompanied by thunder in Kochi Prefecture, so please be careful about how the rain falls.

On the 18th and 19th, it is expected that there will be temporary rain in northern Japan due to the effects of a low pressure system moving near the continent and a front extending from the low pressure system. There are also likely to be localized rain and thunderstorms in eastern and western Japan, mainly along mountains and inland. Even in areas where the weather forecast does not indicate rain, please be aware of sudden changes in the weather in the afternoon.

Around the 20th and 21st, a low pressure system will move across the Sea of Japan. Rain is likely to fall mainly from northern Japan to western Japan on the Sea of Japan side.

From now on, clouds will likely spread across the country due to the influence of humid air. Temperatures will continue to rise with the expansion of the high pressure system, and some areas are expected to experience extreme heat. As the days are expected to continue to be humid and humid, please prevent heat stroke by hydrating properly, replenishing salt intake, and using the air conditioner both day and night.

Weather forecast for today, the 15th (Saturday): Clouds are likely to spread across the country. Be careful of sudden rain and thunderstorms in the afternoon.

2026/08/15 06:46

Today, the 15th (Saturday), clouds are likely to spread around Honshu due to the influx of moist air around the edge of the high pressure system, and there are likely to be localized rain and thunderstorms in the afternoon from Tohoku to Kyushu.



As of 6 a.m., active rain clouds can be seen near Kanto-Koshin and the Kii Peninsula, and there are places where it is raining. In Saitama Prefecture, there are some areas where a level 4 landslide warning has been issued, so please be on alert for landslides in the morning. In other areas of the Kanto-Koshin region, there are places where there will be light showers in the afternoon, and the ground may be loose in some places due to previous heavy rains, so please be careful of landslides even if there is less rain than usual.



From Tohoku to other areas of Kyushu, the weather will be changeable in the afternoon. It is necessary to be careful about sudden rain and thunderstorms, especially in the Hokuriku, Tokai, and Koshin regions, where there is a high probability of lightning occurring in the afternoon, and there is a possibility of locally heavy rain. Please be careful of flooding of roads and sudden rise in river water due to short periods of heavy rain.

Weather for tomorrow 15th (Saturday): Be careful of sudden heavy rain in eastern and western Japan

2026/08/14 17:45

Tomorrow, the area near Japan will be between a tropical cyclone in the Sea of Japan and Typhoon No. 17 in the southeastern sea, and conditions are expected to continue where moist air tends to flow in.
There are many places in eastern and western Japan where it rains, so be careful of localized heavy rain and thunderstorms.



Northern Japan and Hokuriku will be cloudy, but there will be plenty of sunshine. There is a possibility of showers in the morning in southern Hokkaido and Tohoku. It's safe to have a folding umbrella.
There is a possibility of showers in the Kanto region, mainly in the morning. It looks like there will be some sunshine in the afternoon.
There are many places west of the Tokai Sea where the sun will reach in the morning, but clouds will spread in the afternoon. There is a possibility of showers in the Tokai and Kinki regions, especially in the afternoon.
Nationwide, the temperature will rise to around 30c during the day, making it feel hot and humid.

[Beware of sudden heavy rain] The trend of high temperatures and low rainfall continues in western Japan (commentary: weather forecaster Atsuko Miyake)

2026/08/14 14:58

Record-breaking heavy rain is occurring in Chiba Prefecture.



Looking at the precipitation for the 24 hours until 10 a.m. today, Chiba City had 367 mm, which is the highest in recorded history.
Also, the amount of rain that falls in Chiba City during this period is 115mm per month, which means that three times more rain than normal falls in just one day.

In Chiba Prefecture, record short-term heavy rain warnings were announced 25 times, which is also a record number.
Also, from last night until dawn today. Special warnings for heavy rain and landslides were also announced in Chiba Prefecture.



Let's take a look at the cause of why heavy rain was concentrated only in Chiba Prefecture.

Currently, there is a dominant high pressure system near the Chishima Islands, and the movement is slow.
Due to the northeast wind blowing from this high pressure system, humid air was flowing into Chiba Prefecture.
Also, warm, humid air from typhoons and tropical cyclones over the southern ocean was flowing in from the south.
Furthermore, cold air was flowing in from the inland areas of the Kanto region, riding on northwesterly winds.

It is thought that these winds collided in Chiba Prefecture, causing torrential rain.



And this pressure distribution is expected to continue from today to tomorrow.
The easterly wind around the edge of the high pressure system is likely to continue to flow humid air from the Kanto region to the Pacific side of the Tohoku region.

The cold air above is expected to gradually dissipate through tomorrow, but the
pressure distribution will not change much, so the atmosphere is likely to remain unstable into tomorrow.



Now, let's take a look at the rain clouds as the night progresses.
After this, heavy rain and thunderstorms are likely to occur here and there, not only in Kanto, but also from Kyushu to the Pacific side of Tohoku.

Also, in the Kanto region, there is a possibility of extremely heavy rain exceeding 50 mm per hour,
In some cases, heavy rain exceeding 80 mm per hour may fall.



In Chiba Prefecture, the rain will become stronger again after this, and there is a risk of secondary disasters occurring.
After this, there is a possibility of sudden heavy rain.
What should you do if you encounter such sudden heavy rain
When it rains extremely heavily in urban areas, exceeding 50mm per hour, the drainage cannot keep up and the roads become like rivers.

If you do so, rainwater will flow into the underpass and underground facilities.
When it rains heavily, please try to escape from these underground facilities.

And rainwater may flow into the first floor, so
when it is raining heavily, please protect yourself on the second floor or above in a sturdy building.

Please check the radar for the latest information, such as when the rain will stop.
Also, use Kikikuru to check areas that are prone to landslides and flooding.



Although there is heavy rain in Chiba Prefecture, the amount of rain in areas north of the Kanto region is higher than normal.

This is the total precipitation for the 20 days up to yesterday and compared to the normal year.
There are also green signs in areas north of Kanto, which is significantly above normal.

On the other hand, there are brown signs in western Japan, and the rainfall is much lower than normal.
Western Japan is expected to continue experiencing little rain for the next two weeks.



Also, the severe heat is likely to continue in western Japan.
This is the average temperature for 20 days up to yesterday and compared to normal.

In western Japan, temperatures are continuing to rise above normal, with red markings becoming more noticeable.

The high temperature trend is expected to continue for about a month.
Please be careful about heatstroke and managing your crops.



, we will look at the weather in various places.

The unstable atmosphere in the Kanto region will continue into tomorrow.
Please be careful of heavy rain with thunder, lightning strikes, and gusts of wind until dawn.
The heat will not be that intense until the first half of next week, but from the second half of next week the power of the summer Pacific high pressure system will become stronger.

It looks like the intense heat will return from the second half of next week. It also seems like we need to be careful about heatstroke.

[Localized heavy rain again in Kanto] Be wary of secondary damage in Chiba due to localized heavy rain! (Commentary: Weather forecaster Atsuko Miyake)

2026/08/14 14:04

Yesterday there was record heavy rain in Chiba Prefecture.



The 24-hour rainfall up to 10 a.m. today, Friday, the 14th, was 367.0 mm in
Chiba City, which is the highest in recorded history.
This 367 millimeters of rain was more than three times the amount of rain that falls in a month at this time of year.

Yesterday, the 13th (Thursday), record-breaking short-term heavy rain warnings were announced 25 times in Chiba Prefecture,
this is also a record number of times.

Also, from last night until dawn today,
special warnings for heavy rain and landslides were also announced in Chiba Prefecture.

The rain has temporarily stopped, but there is a possibility that heavy rain and thunderstorms will return after this.



Now, let's take a look back at the causes of the torrential rains in Chiba Prefecture.

There is a predominant anticyclone near the Kuril Islands, and the movement is slow.
Moist air around the edge of this high pressure system was flowing into Chiba Prefecture on the northeast wind.

Also, warm, humid air around typhoons and tropical cyclones was flowing in from the south,
making it easy for humid air to flow into Chiba Prefecture.

Furthermore, cold air was flowing in from the inland areas of the Kanto region on northwesterly winds, and
the winds were converging just within Chiba Prefecture.

As a result, the rain clouds did not move much, and heavy rain continued for a long time in similar places.

The same pressure distribution will continue into tomorrow, the 15th (Saturday), and the unstable atmosphere is expected to continue for a long time.



Now, let's take a look at the rain forecast.
After this, linear rain clouds are expected to form again along the coasts of Chiba and Ibaraki prefectures.

We do not know whether a linear precipitation band will form like yesterday, but
the Kanto region will continue to be prone to active rain clouds.

Also, this rain cloud is expected to gradually move westward through the night, but the position of this developed rain cloud is expected to change depending on the wind direction.

Please check the latest status on radar etc.


The date has changed, and even into the early hours of tomorrow (Saturday), active rain clouds are likely to continue in the Kanto region.
In some cases, heavy rain can exceed 80mm per hour.
Please be careful about how it rains after this.




Also, even a small amount of rain increases the risk of landslides in Chiba Prefecture, so even after the rain has stopped, please do not approach cliffs or slopes that are likely to collapse.

The water may rise downstream of the river after the rain has stopped, so please do not go to see the
river or rice fields.

And tonight, some places, such as Tokyo and Kanagawa Prefecture, will see a peak of rain overnight.
It is actually dangerous to evacuate during heavy rain during dark hours.
Please move to a safe place while it is daylight.



, we will take a look at the detailed weather of each place.
The unstable atmosphere will continue in the Kanto region into tomorrow (Saturday).
Especially into the early hours of tomorrow (Saturday), please be careful of heavy rain, thunderstorms, and gusts of wind such as tornadoes.

The cloudy weather will continue into the beginning of next week.
In the second half of next week, the summer Pacific anticyclone will become stronger again.

It looks like we will have another extremely hot day with temperatures exceeding 35 degrees Celsius.
We need to be careful about heat stroke again in the second half of next week.

Weather for today, the 14th (Friday): The Pacific side of the Kanto and Tohoku regions are warned of heavy rain and thunderstorms. Atmospheric instability continues

2026/08/14 08:11

Today, the 14th (Friday), it will likely rain on the Pacific side of the Kanto and Tohoku regions, and in some places it will rain very heavily, accompanied by thunder. It is necessary to be wary of flooding and landslides in low-lying areas. Hokkaido, Hokuriku, Kinki, Kyushu, and Okinawa will experience periods of sunshine.



Today, rain is likely to fall mainly on the Pacific side of the Kanto and Tohoku regions, and there is a risk of thunderstorms and heavy rain on the east coast of the Kanto region, especially in the afternoon.





Even if the rain eases during the day, it is expected to pick up again in the evening. In areas such as southern Kanto and Tohoku, it is necessary to be careful as the rain becomes heavier in a short period of time. Even in Chiba Prefecture, which experienced record heavy rain, there will be places where thunderstorms will occur again.

In other areas, there are many places where the sun will shine, but there will be places where there will be sudden rain or thunderstorms in the afternoon.

Today again, we need to be on high alert for disasters caused by heavy or very heavy rain. Be careful of landslides, flooding, and sudden rises in river water in low-lying areas such as slopes, near cliffs, along rivers, and underpasses. If you feel that things are even slightly different than usual, move to safe higher ground or a designated evacuation center before dark, and frequently check evacuation information from local governments.