Hachiman, Gujo City, Gifu Prefecture, Tajimi City, and Toyota City, Aichi Prefecture recorded "extremely hot days" with temperatures of 40 degrees Celsius or higher. Tomorrow, the 22nd (Wednesday), is also likely to be dangerously hot with temperatures approaching 40 degrees Celsius.

2026/07/21 18:13

Today, the 21st (Tuesday) around 2:00 p.m., AMeDAS observation in Hachiman, Gujo City, Gifu Prefecture, recorded a temperature of 40.0c (newest in observation history), marking the first "extremely hot day" of the year. This is the first time since the Japan Meteorological Agency designated days with maximum temperatures of 40 degrees Celsius or higher as "extremely hot days."
Additionally, at 2:09 p.m., AMeDAS observation in Tajimi City, Gifu Prefecture recorded a temperature of 40.3c, and at 3:12 p.m., 40.1c was observed in Toyota City, Aichi Prefecture. This means that "extremely hot days" were recorded at multiple locations in the Tokai region.



In the ranking of daily maximum temperatures, the top 10 locations recorded temperatures of 39c or higher. As of 5 p.m. today, the 21st, 277 sites experienced extreme heat, making it a record-breaking heat wave.

In major cities, Sendai, Tokyo, Nagoya, Osaka, and Fukuoka recorded extremely hot days with temperatures of 35c or higher, and Nagoya's temperature was the highest in July. Tokyo experienced its first extremely hot day of the year yesterday, the 20th (Monday), and the temperature rose to 36.6c around noon, making it the second consecutive extremely hot day.

#Maximum temperature in major cities
Sapporo 30.7c
*Sendai 35.6c
*Tokyo 36.4c
*Nagoya 39.7c (updated July's No. 1 value)
*Osaka 37.1c
Fukuoka 35.3c
Naha 32.7c
*:Highest temperature recorded this year



Tomorrow, the 22nd (Wednesday), the hot air of midsummer will remain in the skies over western and eastern Japan.
Looking at the minimum temperature on the morning of tomorrow, the 22nd, it is expected to be a tropical night that will not drop below 25 degrees Celsius in many areas. The expected maximum temperature during the day is 40c in Nagoya and Kumagaya (Saitama Prefecture), 39c in Maebashi and Gifu, and many places in western and eastern Japan will have temperatures above 35c.
Please be on guard against heatstroke day and night, and take all necessary measures such as drinking plenty of water, supplementing with salt, and taking adequate breaks.

High probability of lightning forecast in western and eastern Japan; be careful of sudden changes in weather from the afternoon

2026/07/21 13:33

Today, the 21st (Tuesday), atmospheric conditions have become unstable mainly in inland areas and mountains near Honshu due to rising temperatures during the day and moist air.



Looking at the rain cloud radar at 1 p.m., there are scattered rain clouds (indicated by the red radar) in the inland and mountainous areas from Tohoku to Chugoku and Shikoku. Although the range of rain clouds is narrow and localized, there are some places where there are sudden rain and thunderstorms, as seen in AMeDAS observation at 1 pm in Ogouchi, Okutama Town, Tokyo, where moderately heavy rain of 11.0 mm/h was observed.

From the afternoon of today, the 21st, rain clouds and thunderclouds are particularly likely to develop, especially inland and along the mountains. Looking at the predicted probability of lightning, the probability is high in a wide area from southern Tohoku to Kyushu, and there are areas in particular in the northern Kanto and Koshin regions where the probability is over 90%, so we need to be careful about sudden changes in the weather.
Please be careful as sudden rain or thunderstorms can cause rivers to rise in a short period of time and roads to flood. Also, be careful of landslides, lightning strikes, strong gusts of wind, etc. caused by tornadoes. If you see signs of a sudden change in weather, such as seeing black clouds or hearing thunder, please take precautions such as evacuating to a sturdy building.

Dangerous heat that exceeds body temperature - 40 degrees Celsius expected in Kumagaya; heatstroke warning alert the highest this season

2026/07/21 06:51

Today, the 21st (Tuesday), strong sunlight is expected to shine over a wide area due to the Pacific anticyclone covering eastern and western Japan. Extremely hot days with maximum temperatures of 35 degrees Celsius or higher are expected in various places from the southern Tohoku region to Kyushu, and dangerously hot days approaching 40 degrees Celsius are expected in inland areas. In particular, Kumagaya City, Saitama Prefecture, is predicted to have a maximum temperature of 40 degrees Celsius, which could be the first "extremely hot day" of the year. Even in central Tokyo, the weather is expected to be extremely hot, with temperatures expected to reach 36 degrees Celsius. Please take all possible measures to prevent heat stroke.

The predicted maximum temperature in each region is Sapporo 29c, Sendai 34c, Tokyo 36c, Kanazawa 34c, Nagoya 39c, Osaka 37c, Kochi 35c, and Fukuoka 33c.



The Ministry of the Environment and the Japan Meteorological Agency have issued heat stroke warning alerts from Tohoku to Okinawa, targeting 44 areas in 42 prefectures, the highest number this season. This will also be the first announcement of this year in Gifu and Osaka prefectures.

#Heatstroke Warning Alert Announcement Target Areas
Miyagi Prefecture, Fukushima Prefecture, Ibaraki Prefecture, Tochigi Prefecture, Gunma Prefecture, Saitama Prefecture, Tokyo, Chiba Prefecture, Kanagawa Prefecture, Nagano Prefecture, Yamanashi Prefecture, Shizuoka Prefecture, Aichi Prefecture Prefectures: Gifu, Mie, Niigata, Toyama, Ishikawa, Fukui, Shiga, Kyoto, Osaka, Hyogo, Nara, Wakayama, Okayama, Hiroshima, Shimane, Tottori, Tokushima, Kagawa, Ai Hime prefecture, Kochi prefecture, Yamaguchi prefecture, Fukuoka prefecture, Oita prefecture, Nagasaki prefecture, Saga prefecture, Kumamoto prefecture, Miyazaki prefecture, Kagoshima prefecture (excluding Amami region), Okinawa prefecture (Okinawa main island region), Okinawa prefecture (Daitojima region), Okinawa prefecture (Yae) Mountain regions)

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, please use the air conditioner as appropriate to stay indoors in a cool environment, and take precautions against heatstroke indoors.

Today's 21st (Tuesday) weather: Sunny and dangerously hot from eastern to western Japan. Heat stroke warning

2026/07/21 06:22

The rainy season front is expected to remain in Tohoku today, the 21st (Tuesday), after the holidays. On the other hand, eastern and western Japan will be covered by the Pacific anticyclone and will be exposed to strong sunlight.



There are times when clouds spread in Hokkaido, but most of the time it will be sunny. There is a possibility of showers in parts of the Pacific Ocean in the afternoon, so it's a good idea to bring a foldable umbrella.
In the northern part of Tohoku, clouds tend to spread, and there are likely to be some places where it will rain. It will be safe to have rain gear when going out.

From the southern Tohoku region to Kyushu, there are many places where the sun reaches, and the intense heat continues. The maximum temperature in many places will exceed 35 degrees Celsius, and it is expected to be dangerously hot, exceeding body temperature. Be careful not only of outdoor heatstroke but also of heatstroke indoors.
In addition, as temperatures rise, rain clouds are expected to develop locally in the afternoon, mainly along the mountains and inland. You also need to pay attention to changes in the sky.

Tomorrow, the 21st (Tuesday), there is a risk of disaster-level heat in the Tokai and Kanto regions; 40 degrees Celsius expected in Kumagaya. Will this be the first extremely hot day of the year

2026/07/20 18:39

Tomorrow, the 21st (Tuesday) after the holidays, the Pacific anticyclone will become even stronger, so the intense heat is likely to continue mainly in the Tokai and Kanto regions.



In particular, Kumagaya City, Saitama Prefecture, is expected to experience intense heat of 40 degrees Celsius. This will be the first time this year that we have had such a hot day nationwide. Temperatures in Nagoya and Gifu are also expected to reach 39 degrees Celsius, which is just one step away from an extremely hot day.



The severe heat continues in Western Japan, with temperatures in places like Kyoto and Okayama likely to reach 37 degrees Celsius, exceeding body temperature.



A [Heatstroke Warning Alert] has been issued widely for tomorrow, mainly in Kyushu and southern Tohoku.
Please be extremely careful about heatstroke day and night, drink plenty of water and salt, and use air conditioning even at night to prevent heatstroke.




The Ministry of the Environment's "Heatstroke Prevention Information Site" updates information on the risk of heatstroke (Heatstroke Warning Alert) on a daily basis.
Please check the alert level in your area and act accordingly.

Also, the heat level has risen a notch this week, and the disaster-level heat is expected to continue from tomorrow onwards. Avoid going out in strong sunlight as much as possible and try to stay in a cool place.

A series of extremely hot days: Central Tokyo records its first extremely hot day of the year

2026/07/20 16:58

Today, the 20th (Monday), many areas around Honshu were covered in high pressure and were sunny, with strong sunlight shining down and making it extremely hot.



In the inland areas of eastern and western Japan, there are many places where the heat is dangerously high, exceeding body temperature. As of 3:20 p.m., the daily maximum temperature was 39.4c in Katsunuma, Koshu City, Yamanashi Prefecture, 38.6c in Toyota City, Aichi Prefecture, and 38.5c in Hatoyama, Saitama Prefecture. It was extremely hot, with temperatures exceeding 38 degrees Celsius in the top 10 locations with the highest daily temperatures.
As of 3 p.m. today, the 20th, the number of locations that have recorded extremely hot days of 35 C or higher is 243. In central Tokyo, AMeDAS observations have observed temperatures of 35 C or higher, marking the first extremely hot day of the year. As of 3:10 pm on the 20th, the highest temperature in Tokyo has reached 36.1c.



Tomorrow, the 21st (Tuesday), will have a similar atmospheric pressure distribution as today, the 20th (Monday). It is likely that there will be some rain on the Sea of Japan side of northern Japan, where the front is stationary, but areas from the southern Tohoku region to Kyushu and the Nansei Islands will be covered by a midsummer high-pressure system, and the maximum daytime temperature will likely rise to around 35c in many places. Inland, there are likely to be places where the heat is dangerously close to body temperature. Kumagaya City in Saitama Prefecture and Nagoya are expected to experience 39 degrees Celsius, while Maebashi, Kofu, Gifu and other areas are expected to experience 38 degrees Celsius.

Please continue to be extremely careful about heat stroke, drink plenty of water and salt, and take adequate breaks.

The end of the rainy season has been announced in the Tokai and Kanto regions. The severe heat will continue day after day, and there is a warning for heat stroke.

2026/07/20 12:21

On Monday, the 20th, Marine Day, the Japan Meteorological Agency announced that the rainy season appears to have ended in the Tokai and Kanto-Koshin regions.



The rainy season ended one day later than normal in the Kanto-Koshin region, and 22 days later than last year. In the Tokai region, the end of the rainy season was announced one day later than normal and 23 days later than last year.

*The rainy season is a seasonal phenomenon, and there is an average "transition" period of about 5 days between the start and end of the rainy season. In addition, the announcement of the start and end of the rainy season is preliminary information, and will be reconsidered in consideration of weather changes from spring to summer, and may be revised at a later date.



From now on, the area around Honshu will be covered in high pressure for many days, and the severe heat is expected to continue day after day, especially in eastern and western Japan. The temperature will not drop much at night, and the night will continue to be tropical.
From tomorrow, the 21st (Tuesday) after the holidays, the predicted maximum temperature in Tokyo will be 35 degrees Celsius or higher every day, and in Nagoya, the 22nd (Wednesday) and 23rd (Thursday) may be extremely hot days of 40 degrees Celsius.

Please be extremely careful about heatstroke day and night, drink plenty of water and salt, and use air conditioning even at night to prevent heatstroke.

Beware of sudden changes in weather in eastern and western Japan today, the 20th (Monday/Marine Day). There is a risk of thunderstorms mainly along the mountains in the afternoon.

2026/07/20 07:40

Today, the 20th (Monday/Marine Day), many parts of eastern and western Japan are expected to be covered in high pressure and be mostly sunny, but in the afternoon, people should be careful of sudden thunderstorms especially along the mountains.
When going out, please bring rain gear and pay attention to changes in the sky, especially if you are planning to take part in outdoor leisure activities.



Looking at the weather forecast at 6:00 pm today, it is predicted that it will be mostly sunny in eastern and western Japan, but that it will rain in places, mainly along the mountains.



Looking at the probability of a lightning strike at 6pm today, the probability of a lightning strike is high mainly along the mountains of eastern and western Japan.

Due to the rise in daytime temperatures and the influence of warm, humid air flowing in from the south, the atmospheric conditions will become unstable in the afternoon, leading to localized heavy rain with thunderstorms.
Please be careful of flooding of low-lying land, rising river water, and landslides. Also, be careful of gusts of wind such as lightning and tornadoes.
Please be aware of changes in the sky, and if there are signs of a developing cumulonimbus cloud approaching, please take precautions such as moving inside a building.

Weather for tomorrow 20th (Monday): Extreme heat continues from Okinawa to southern Tohoku

2026/07/20 05:21

The front is expected to stay near northern Tohoku, and a low pressure system is expected to pass over Hokkaido. Eastern and western Japan will be within an area of high pressure.



Many areas from Okinawa to the southern part of Tohoku are exposed to sunlight, so it is likely to be extremely hot. It will be hot and humid from the morning, with temperatures rising to around 35c during the day, and the temperature is not expected to drop much at night. As the southerly winds weaken, temperatures will tend to rise on the Pacific coast and inland. Take all possible precautions to prevent heat stroke, use a hat and parasol when going out, take frequent breaks, and drink water. The atmospheric conditions will become unstable in the afternoon, especially along the mountains, so please be careful of sudden strong rain and thunder.
Clouds are likely to spread in northern Tohoku and Hokkaido, and there will be occasional rain in some places. Please bring a folding umbrella when going out. Even if there is little sunlight, the humidity is high and it can feel hot and humid.



It is well known that tomorrow is Marine Day, but it is also the day of the moon landing. The anniversary is commemorated in honor of Apollo 11's successful landing on the moon. The moon will be visible late at night over a wide area of western and eastern Japan. Please take this opportunity to look up at the sky.

Weather for the week: Rainy skies in the Tohoku region. Be careful of dangerous heat and sudden rain in eastern and western Japan.

2026/07/20 04:13

The weather for the next week is expected to continue to be cloudy and rainy in the Tohoku region due to the influence of the seasonal rain front, while eastern and western Japan are expected to have many sunny days.
However, even if the weather is sunny, there is a possibility of rain showers mainly along the mountains due to rising daytime temperatures and warm, humid air flowing in from the south. Please be careful of sudden changes in the weather.



This week, the rainy season front is expected to stay near the northern part of Tohoku. There will be many rainy days, especially in the northern Tohoku region.
During the weekend from the 25th (Saturday) to the 26th (Sunday), a frontal low pressure system is expected to move eastward near Tohoku, so rain will spread over the Tohoku and Hokuriku regions.

Hokkaido has many cloudy and sunny days.
Eastern and western Japan will have many sunny days covered by high pressure from the south.
However, local atmospheric conditions may become unstable due to rising daytime temperatures and warm, humid air flowing in from the south. Even if it is sunny, there is a possibility of thunderstorms in the afternoon, mainly along the mountains. Please be careful of sudden changes in the weather.

If you notice that pitch black clouds are approaching, you hear thunder, or suddenly a cold wind is blowing, move into a sturdy building.
Heavy rain brought by well-developed cumulonimbus clouds can fall heavily over a small area in a short period of time. Be careful of lightning strikes, gusts of wind such as tornadoes, rising river waters, and flooding of low-lying areas.




Over the next week, temperatures are expected to be higher than normal in many places in northern and western Japan. It is predicted that a wide area of Kanto-Koshin, Tokai, and western Japan, including Tokyo, will experience extremely hot days with temperatures exceeding 35 degrees Celsius every day, while Nagoya is expected to experience extreme heat of 40 degrees Celsius from the 22nd to the 23rd.

Please take steps to prevent heat stroke, such as hydrating frequently, adding an appropriate amount of salt, and using a parasol or hat when outdoors. Since there are many places where the temperature is over 25 degrees Celsius in the tropics, make sure to use the air conditioner properly indoors even at night and don't overdo it.
Also, please check the heatstroke warnings issued jointly by the Japan Meteorological Agency and the Ministry of the Environment, and consider refraining from outdoor activities on the days when they are issued in your area.