[Typhoon Information] Typhoon No. 18 is moving north-northwest through the Mariana Islands. Be careful of its future course.

2026/08/21 16:39

As of 3:00 pm on Friday the 21st, Typhoon No. 18 was moving north-northwest near the Mariana Islands at a speed of 20 kilometers per hour.

It is expected to become a strong force on the morning of tomorrow, the 22nd, and continue to move north-northwest.



It will become a very strong force on the 23rd, pick up speed slightly, change course to the west-northwest, and move toward the waters near Ogasawara.
In the Ogasawara Islands, please be careful of rising waves and strong winds from the 23rd to the 24th.

In addition, there is a risk that it will continue to maintain very strong strength and move west-northwest across the south of Japan, approaching the Okinawa region.
Depending on the path of the typhoon, there is a risk of heavy rain, heavy storms, and severe storms in the Daitojima region from the 24th to the 26th, and
warning-level heavy rain, heavy storms, and severe storms in the Okinawa main island region from the 25th to the 26th.

Please pay attention to the latest typhoon information that will be announced in the future.

Kanto-Koshin: Be wary of high temperatures from the weekend - take precautions against heatstroke

2026/08/21 15:57

The Kanto-Koshin region is expected to be widely covered by the
anticyclone from this weekend until the 27th (Thursday). As warmer than normal air flows into the sky above
and the
sunshine shines through, temperatures in various locations tend to rise significantly.



Furthermore, as Typhoon No. 18 is expected to move south of Japan, warm and humid air is expected to flow into the Kanto region.
As a result, there will be some extremely hot days with maximum temperatures of 35 C or higher, especially inland, and the severe heat is expected to continue.



In Kofu, the predicted maximum temperature on Saturday the 22nd is expected to be 35c, and on Tuesday the 25th, temperatures are expected to reach 38c in Kumagaya and 37c in Maebashi/Kofu, making it dangerously hot.
Even in central Tokyo, temperatures are expected to reach 35 degrees Celsius, raising the risk of heat stroke in a wide area.



High temperature conditions can last for several days, so it is essential to take measures to prevent heat stroke, such as frequent hydration, appropriate use of air conditioning, and avoiding long hours of work outdoors.
Refer to the heatstroke warnings that are announced and try to take reasonable actions to protect yourself from the heat.

Today, the afternoon of the 21st, watch out for sudden thunderstorms and heavy rain in the Kanto-Koshin region

2026/08/21 13:46

Today, the 21st (Friday), a front is extending from the Sea of Japan through the Tohoku region to the east of Japan.
Due to the influence of this front, developed rain clouds are covering the Tohoku-Hokuriku and Kanto-Koshin regions. Today in the morning, extremely heavy rain was observed at Wajima in Wajima City, Ishikawa Prefecture, with 74.0 mm, and in Nanto Takamiya in Nanto City, Toyama Prefecture, 69.0 mm.
In the Kanto-Koshin region, heavy rain of 43.0 mm was observed at Kasadake in Takayama Village, Kamitakai District, Nagano Prefecture, and 39.5 mm at Tokuda in Hitachiota City, Ibaraki Prefecture.



Atmospheric conditions in the Kanto-Koshin region are extremely unstable due to the effects of warm, humid air heading towards this front, rising temperatures during the day, and a trough in the atmospheric pressure above.
Currently, rain clouds have developed in Saitama and Chiba prefectures in the southern Kanto region, as well as the Tama region of Tokyo.



After this, rain clouds that have developed will move into central Tokyo, causing heavy rain and thunderstorms.
Please be careful and be on guard against flooding of low-lying areas, rising river waters, and landslides late into the evening of today, the 21st (Friday). Also be careful of strong wind gusts such as lightning and tornadoes.

Also, in the Kanto-Koshin region, the atmospheric conditions will be extremely unstable in the afternoon of tomorrow, the 22nd (Saturday), and there will be places where there will be heavy rain accompanied by thunder or very heavy rain. Please continue to be careful and vigilant.

[Rain Forecast]
The predicted 1-hour rainfall on Friday the 21st is high in the following areas:
Northern Kanto Region 50mm
Kanto Region Southern area: 40mm
Koshin region: 40mm
The predicted hourly rainfall on Saturday the 22nd is high,
Northern Kanto region: 30m m
Southern Kanto region 40mm
Koshin region 30mm
Forecasted from 12:00 p.m. on Friday the 21st to 12:00 p.m. on Saturday the 22nd 24-hour precipitation is high in the following areas: Northern Kanto region 100mm
Southern Kanto region 80mm
Koshin region 80mm

[Typhoon information] Typhoon No. 18 will continue to intensify as it moves northwest. It will approach the main island of Okinawa around the 26th.

2026/08/21 07:36

As of 6 a.m. today, Friday the 21st, Typhoon No. 18 is moving northwestward while intensifying over the Mariana Islands.

#Typhoon No. 18 21st (Friday) 6:00 a.m.
==================
Center location Mariana Islands
Movement speed North-northwest 20km/h
Central pressure 990hPa
Maximum wind speed 25m/s (near the center)
Maximum instantaneous wind speed 35m/s
===================

Typhoon No. 18 will continue to develop and move northwest, gradually becoming a "strong" force with a storm area. It is expected to develop into a "very strong" force around the 23rd, with maximum wind speeds near the center of the storm reaching 45 m/s and maximum instantaneous wind speeds of 65 m/s.
In the Ogasawara Islands, swells from the typhoon have been spreading since around the 23rd, and there is a risk of warning-level high waves in coastal areas, so vigilance is required.



After that, Typhoon No. 18 is expected to approach Daito Island around the 25th, and near the main island of Okinawa around the 26th. Depending on future forecasts, there is a possibility that southern Kyushu will enter the typhoon's strong wind region.
There is a risk of heavy rain in Okinawa from around the 26th. Please pay close attention to future typhoon information and take typhoon countermeasures as early as possible.

Also, in areas on the Pacific side of western and eastern Japan near Honshu, which are far from the typhoon, there is a risk that the warm, humid air from the typhoon will spread the rain and cause high waves with swells in coastal areas. Please pay close attention to the latest weather information that will be updated in the future.

Weather forecast for today, the 21st (Friday): Severe summer heat mainly in western Japan; watch out for localized heavy rain from Tohoku to Okinawa

2026/08/21 06:52

Today, the 21st (Friday), a front will pass near northern Japan. Developed rain clouds can be seen in the southern Tohoku and northern regions near the front, and lightning has been detected in some places. As of 5:40 a.m. in Hokuriku, heavy rain was observed in Wajima City, Ishikawa Prefecture, with an hourly rainfall of 31.0 mm, and a level 3 heavy rain warning was issued.



In the Tohoku and Hokuriku regions near the front, it will continue to rain easily after this, and there is a risk of extremely heavy rain of 50 mm or more per hour accompanied by localized thunderstorms.
In areas west of the Kanto region, warm, humid air will flow toward the front, and as daytime temperatures rise, rain clouds and thunderclouds will likely develop. There is a high probability of lightning occurring in western and eastern Japan, mainly in inland areas. Even in areas where there may be some sunshine in the morning, the weather is expected to change rapidly in the afternoon, with localized areas of heavy rain accompanied by thunderstorms, especially inland.
In Okinawa and the Sakishima Islands, rain is likely to fall easily due to the effects of a tropical cyclone, and localized heavy rain is likely.
In areas from Tohoku to Okinawa, please be careful and take precautions against flooding of low-lying areas, flooding of roads, and sudden rises in rivers due to localized heavy rain.



During the day, it will be extremely hot, especially in western Japan. The predicted maximum temperature is expected to be 37 degrees Celsius in Kumamoto and Saga, and there is a risk that it will be dangerously hot, exceeding body temperature. In many other parts of western Japan, the temperature will be around 35 degrees Celsius, and in Osaka and Kyoto, extremely hot days of 35 degrees Celsius are expected. In many places in northern and eastern Japan, the temperature is around 30 degrees Celsius, so you will experience a hot and humid experience.
Please continue to take precautions against heatstroke.

Latest 1-month forecast: Severe lingering summer heat across the country, with some places reaching "very high temperatures"; Western Japan is worried about drought

2026/08/20 19:56

On the 20th (Thursday), the Japan Meteorological Agency announced the latest monthly weather forecast for the next month.



The average sea level pressure for one month based on the forecast model is that it is likely that western and eastern Japan will be covered by the Pacific anticyclone. Northern Japan is expected to experience periods when it is susceptible to low pressure. Additionally, atmospheric pressure is expected to be lower than normal in the southeast of Japan, and areas near Okinawa and Amami are expected to be susceptible to typhoons and humid air, especially during the first half of the period.
The altitude around 1500m near Japan is expected to be higher than normal, especially in northern Japan, and the whole country is expected to be covered in warm air.



From now on, temperatures will be higher than normal and the severe heat will continue in all regions except Okinawa and Amami. Western Japan has been covered in warm air since July, and the temperature has continued to be high, but the temperature will continue to be high for the next month or so, and the lingering heat will be severe.



In particular, from around the 26th of next week until around September 3rd, a wide area from the Pacific side of Hokkaido to northern Kyushu is expected to experience ``considerably high temperatures'' of levels once every 10 years. In some places, extremely hot days of over 40 degrees Celsius will be recorded, and in other areas there is a risk that the temperature will reach dangerous levels above body temperature.
Be wary of heatstroke and do not neglect heatstroke prevention measures such as frequent hydration, salt supplementation, and taking adequate breaks.

The Sea of Japan side of Hokkaido is susceptible to the effects of atmospheric pressure troughs, and precipitation will likely be at or above normal. Due to the effects of typhoons and humid air, Okinawa/Amami is expected to experience more precipitation than normal.
On the other hand, western Japan is expected to be more susceptible to the effects of the Pacific anticyclone and less likely to be affected by humid air. The closer you are to the Pacific Ocean, the more sunny days there will be, and the amount of precipitation is expected to be lower than normal.



In many places in western Japan, the amount of precipitation over the past month has been well below normal, and there will likely be fewer rainy days over the next month as well. In some areas, the water storage rate of dams has already dropped significantly and water intake restrictions are in place. Please try to conserve water as much as possible.

Weather for tomorrow 21st (Friday): Rain in Tohoku and Kanto

2026/08/20 17:51

As the front passes through northern and eastern Japan, it will likely rain more easily in Tohoku and eastern Japan. Western Japan will be covered in high pressure and it will be sunny, but the atmospheric conditions are unstable and there is a risk of sudden rain and thunderstorms. The Nansei Islands continue to experience heavy rain due to the effects of tropical cyclones, so it's a good idea to bring an umbrella with you.



There will be periods of cloudy weather in Hokkaido and northern Tohoku, but it is expected to be mostly sunny. Temperatures are expected to rise to around 30c.
Southern Tohoku, Hokuriku, and northern Kanto will experience more rain as the front moves southward. Even if it's not raining in the morning in northern Kanto, the weather will go downhill in the afternoon, so don't forget your umbrella. There is a possibility of rain in places in the southern Kanto region from the afternoon, so it's a good idea to bring an umbrella.
From the Tokai region to the west, there are many places where it is sunny. It will continue to be as hot as body temperature, especially in Kyushu and China. Please be extremely careful about heat stroke. Atmospheric conditions will become unstable in the afternoon, with the possibility of localized thunderstorms, especially inland.
It looks like it will be a day in Okinawa where you won't be able to do without your umbrella.

[Ocean summary (August 9th to August 15th, 2026)] After the passage of Typhoon No. 15, sea surface temperature drops in a wide range from the East China Sea to the Kanto coast

2026/08/20 13:45

After the passage of Typhoon No. 13 and Typhoon No. 15, areas with sea surface temperatures lower than normal can be seen over a wide area east of Japan and
from the East China Sea to the Kanto coast.

Below is the ocean summary (August 9th to August 15th, 2026)



#Pressure distribution and waves
From August 9th to 10th, a large and extremely strong typhoon No. 13 moved westward through the East China Sea. Fierce drought near the center of the typhoon. Wave height was around 2m near the Tsushima Strait. On the 10th, Typhoon No. 15 moved northwest through the east of Japan. Wave height exceeded 3 meters in eastern Japan. On the 11th, Typhoon No. 15 moved westward and made landfall in southern Ibaraki Prefecture at night. Waves were rising on the Pacific side of eastern Japan. On the 12th, Typhoon No. 15 moved towards the Sea of Japan and turned into a tropical cyclone. Wave height around 2m in eastern Japan and the central to western parts of the Sea of Japan. From the 13th to the 15th, the waves in the seas around Japan gradually became calmer as the area was gently covered by an anticyclone centered around the Kuril Islands.



#Sea surface temperature
Sea surface temperatures were near normal in the western part of the Japanese Sea, but higher than normal in the northern part, with maximum temperatures of 3 C above normal. In the East China Sea and the waters near the Nansei Islands, areas of higher-than-normal waters have shrunk, and areas of lower-than-normal temperatures can now be seen. Areas of lower-than-normal waters expanded off the coasts of Shikoku, Kanto, and Sanriku, with temperatures up to 2 C below normal. Off the southeast coast of Hokkaido, areas of higher-than-normal waters have expanded. Sea areas near the Chishima Islands and the Sea of Okhotsk appeared to be much higher than normal, and the sea near the Chishima Islands was up to 5c higher than normal

Weather for today, the 20th (Thursday): Extreme heat continues in western Japan, including Kyushu; rain is likely to occur in northern Japan.

2026/08/20 09:14

Today, August 20th (Thursday), it will be sunny in many places from western Japan to the Kanto region, while the intense heat is expected to continue in Kyushu and other areas. On the other hand, due to the front and moist air, it will be rainy in northern Japan and Hokuriku.





Western Japan and the Tokai region are often sunny due to the influence of high pressure, and temperatures are rapidly rising. During the day, there are places where the heat is comparable to body temperature, so the risk of heat stroke is extremely high and maximum vigilance is required.

When you go out, choose a shaded area to walk in, stay hydrated frequently, and take adequate breaks. In particular, it is necessary to limit outdoor work and exercise and pay close attention to your physical condition.



The Kanto region will be a little cloudy due to the damp air, but the sun is expected to shine. It will be a midsummer day in Tokyo, at 33c, and it will be hot and humid during the day.
In the afternoon, rain clouds will develop mainly along the mountains, and there is a possibility of sudden rain even in the plains, so please bring a folding umbrella with you.

Northern Japan is experiencing clouds and rain in some places due to the front. Even if it's not raining when you go out in the morning, it's a good idea to bring a large umbrella.

[Latest typhoon information] Typhoon No. 18 (Soudel) may approach Ogasawara and Okinawa main island from next week. Pay attention to future trends.

2026/08/20 07:45

As of 06:00 today, the 20th (Wednesday), Typhoon No. 18 (Sawdel) is moving north-northwest at a speed of 25 km/h near the Truk Islands.
The central pressure is 996hpa, and the maximum wind speed near the center is 20m/s.

#Typhoon No. 18 (Sawdel) 20th (Thu) As of 06:00
===================/brCenter position Sea near Truk Islands
Traveling speed North-northwest 25km/h
Central pressure 996hPa
Maximum wind speed 20m/s (near the center)
Maximum instantaneous wind speed 30m/s
==================




This typhoon is expected to continue to develop and become very strong by the weekend. There is a possibility that it will approach Ogasawara and the main island of Okinawa next week, so we need to pay close attention to its trends.

Although there is still a wide range of predictions regarding the course of the storm, there is a possibility that winds will become stronger in the Ogasawara Islands from around the 22nd (Saturday), and the waves may gradually become higher due to the swells from the typhoon. Also, depending on future forecasts, there is a risk that the area could enter the typhoon's strong wind range, so please pay attention to the latest typhoon information that will be updated in the future.

After that, there is a possibility that it will approach the main island of Okinawa by the middle of next week. Furthermore, even if the typhoon is far from Honshu, the inflow of warm, humid air from the typhoon can have a significant impact on the weather near Honshu. Please check back regularly for future information.