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.

Weather for tomorrow the 20th (Thursday): It tends to rain in northern Japan Weather for tomorrow, the 20th (Thursday): It tends to rain in northern Japan

2026/08/19 17:34

A cold front is expected to move south across northern Japan, and a tropical cyclone is expected to approach the Nansei Islands.



Northern Japan will have clouds due to the influence of the front, and it will rain over a wide area. Even if it's not raining in the morning, bring an umbrella with you when you go out. Due to the lack of sunlight, the maximum temperature is expected to be around 30c.
In the Kanto region, clouds will spread more easily due to the influence of humid air. There will be times when the sun will be shining, and it is expected to be extremely hot.
From the Tokai to the west, there are many areas covered in high pressure that will be sunny, and it will likely be dangerously hot, comparable to body temperature. The heat and humidity will continue into the night. Please be extremely careful about heat stroke.
Thick clouds will spread over Okinawa and it will rain. There is a risk of heavy rain with thunder in some places.

[Typhoon Information] Typhoon No. 18 (Souderu) occurs near the Truk Islands

2026/08/19 13:41

Around noon today, Wednesday the 19th, a tropical cyclone that was developing near the Truk Islands became Typhoon No. 18.

#Typhoon No.18 19th (Wednesday) As of noon
==================
Center location Near Truk Islands
Movement speed Almost stagnant
Central pressure 1002hPa
Maximum wind speed 18m/s (near the center)
Maximum instantaneous wind speed 25m/s
==================



Typhoon No. 18 is expected to continue to develop and move northwest.
It is expected to move over the sea south of the Ogasawara Islands by around 9:00 on the 23rd, with maximum wind speeds near the center reaching 30m/s, and is expected to be accompanied by stormy winds. It is expected to become a "strong" force around 9:00 on the 24th and continue to move westward.



Although there is still some uncertainty in predicting the course, winds are expected to strengthen in the Ogasawara Islands and waves are expected to gradually rise due to swells from the typhoon. Also, depending on future forecast changes, we cannot deny the possibility that the typhoon will enter the storm region. Please pay attention to the latest typhoon information that will be updated in the future.

Depending on the future course of Typhoon No. 18, it may approach the main island of Okinawa from next week onwards. 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 the future information carefully.

Severe summer heat continues today mainly in western Japan; 38 degrees Celsius expected in Kumamoto; heat stroke warning

2026/08/19 06:58

Yesterday, the 18th, temperatures rose mainly in western Japan, making it an extremely hot day in 58 locations. In some places, it was as hot as body temperature, with temperatures reaching 37.3c in Oita City and 36.6c in Kumamoto City.

Today, the 19th (Wednesday), many places from western to eastern Japan will be covered in high pressure and will be sunny, with severe lingering heat expected mainly in western Japan.
Today's highest temperature is expected to be 38 degrees Celsius in Kurume City, Fukuoka Prefecture, Saga City, and Kumamoto City. Please continue to take thorough measures to prevent heat stroke.

In addition, the predicted maximum temperatures in each city are Sapporo 28c, Sendai 30c, Tokyo 34c, Nagoya 34c, Kanazawa 34c, Osaka 35c, Kochi 34c, and Fukuoka 35c. It can feel hot and humid in many places, so in addition to staying hydrated frequently, it's a good idea to wear breathable clothing.



The Ministry of the Environment and the Japan Meteorological Agency have issued heatstroke warning alerts from western Japan to Kanto, covering 14 prefectures.

#Area covered by heat stroke warning alert
Tokyo, Kyoto, Wakayama, Hiroshima, Shimane, Tottori, Kagawa, Ehime, Fukuoka, Oita, Nagasaki, Saga, Kumamoto, 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 heat stroke indoors.

Today's weather (Wednesday 19th): Sunny from Tohoku to Kyushu; watch out for thunderstorms in Okinawa

2026/08/19 06:34

Today, the 19th (Wednesday), there will continue to be a high pressure system centered over the east of Japan, and many parts of Honshu will be sunny. On the other hand, due to the approaching tropical cyclone, it seems that Okinawa will need to be careful about the intensifying rain.



Clouds tend to spread in Hokkaido, and there are many places where it will rain, especially on the Sea of Japan side. Please bring rain gear when going out. . There is a possibility of showers even on the Pacific side, so it's a good idea to bring a folding umbrella.

It is expected to be sunny in many places from Tohoku to Kyushu. Continuing from the previous day, temperatures will continue to rise in western Japan, so it is important to be careful about heatstroke. In addition, atmospheric conditions will become unstable in the afternoon, and rain clouds are expected to develop locally, mainly along the mountains. If you are going for leisure activities in the mountains, please be aware of changes in the sky.

Okinawa is expected to experience heavy rain and strong winds due to the effects of a tropical cyclone. There is a risk of heavy rain and thunderstorms mainly in the Sakishima Islands, so please be careful of heavy rain, strong winds, and high waves.

New typhoon forecast: The next one will be Typhoon No. 18, so be careful in the future

2026/08/19 01:44

The Japan Meteorological Agency announced that the tropical cyclone currently developing in the Truk Islands is expected to develop into a typhoon within the next 24 hours.
The next occurrence will be ``Typhoon No. 18'', making it the fifth typhoon to occur this month.

#Typhoon No. 18 19th (Wednesday) 0:00
==================
Center location Near Truk Islands
Movement West Slowly
Central pressure 1004 hPa
Maximum wind speed 15 m/s (near the center)
Maximum instantaneous wind speed 23 m/s
==================



The typhoon is expected to move northwards around the 20th (Thursday), change its course to the northwest, and move northwest across the Mariana Islands with strong force until the 23rd (Sunday). There is a great deal of uncertainty about the course that will follow, but please pay close attention to future information as it may have an impact on Japan.