Tokyo: First Midsummer Day of the year, the rainy season front has become more active since tomorrow, warning-level heavy rain [weekly weather]

2025/05/20 15:58

Today, May 20th, the rainy season front is stagnating away from the south of Japan, with many areas in the west and eastern Japan where there are sunny days.

The temperature has risen, and the highest temperature until noon is 32.8c in Maehara, Itoshima City, Fukuoka Prefecture, 32.0c in Hachioji City, Tokyo, 31.0c in Naha City, and 30.0c in Central Tokyo, 30.0c in many places this year.

Closs has exceeded 30 C since the morning in central Tokyo, and
This is the first "midsummer day" of the year.



If tomorrow, the 21st (Wednesday), the rainy season front will move north to southern Kyushu and is expected to stagnate near southern Kyushu until Thursday,
22nd (Thursday).

Warm and humid air flows towards the rainy season front
/BThe front will become more active, with some areas where heavy rain will fall, mainly in southern Kyushu.



In Kagoshima and Miyazaki prefectures, heavy rain may occur at the
warning level from tomorrow morning.

It is expected that the area of heavy rain will expand even further on the 22nd (Thursday), and currently, warning-level heavy rain is only expected to be expected on the Izu Islands, but
Caution and caution in other areas as well.



Since then, the front is expected to stagnate near Honshu with north-south vibrations, and even in areas where the rainy season is not in progress
/Cannot be clear weather with cloudy and rainy weather.


The front of the Nansei Islands will likely be stagnant from around Thursday the 22nd, so Okinawa may also announce the "rainy season" to begin later this week.

As frontline activities will become more active next weekend, heavy rain is likely to occur, especially on the Pacific side of western Japan.



/B: In southern Kyushu, where the rainy season begins earlier than usual, there is a greater amount of rain, so please stay away from steep cliffs and slopes and avoid getting close to flooded rivers.


Also, rain is expected in Tokyo on this weekend, and
/Ray may rain on the weekend for the third consecutive week.


Depending on future movements of the front line, there is a possibility that heavy rain will occur in eastern Japan, such as Kanto, so please be aware of the latest information.

In eastern and western Japan, there are many midsummer days above 30 C. Please be careful about your health

2025/05/20 10:12

Today, the 20th, the area around Honshu will be covered in a gentle high pressure system, and the temperature will be sunny and high from Kanto to Chugoku and Shikoku.
There are many midsummer days with a maximum temperature of over 30 C, and it seems that many places will be the hottest this year.




In particular, inland areas in Chichibu City and other cities, we are forecasting a hot day with a maximum temperature of 35c.



It's a hot day like midsummer, so please be careful when managing your health, such as preventing heat stroke.
To prevent heat stroke, it is important to stay hydrated frequently and avoid the heat.
It is important to avoid direct sunlight, especially when going out, by wearing a parasol or hat, and using the shade.
Also, don't worry about being indoors, and try to keep up with proper hydration and temperature control.



Specific measures to prevent heatstroke are as follows.

1. Avoid the heat:
When going out: Wear a parasol or hat and use the shade. Avoid going out during hot times.
Indoor: Make sure to control the temperature appropriately (use air conditioners and fans appropriately). Make sure to ventilate frequently.
When active: Don't overdo it on hot days and take frequent breaks.

2. Hydration:
Relax: Refreshing hydration frequently during the hot season to prevent dehydration.
Drinks suitable for hydration: Barley tea, oral rehydration solutions, sports drinks, etc. are suitable.

3. Salt supplement:
Salt supplement when sweating: It is also important to replenish the salt that is lost along with sweat.
Foods suitable for replenishing salt: Add a little salt to umeboshi, salted kelp, rice balls and other foods.

4. Clothing:
Breathable Clothing: Wear clothes made of breathable materials (cotton, linen, etc.).
Moisture-absorbing and quick-drying underwear: Choose underwear that is excellent in moisture-absorbing and quick-drying.

5. Health management:
Notes when you are not feeling well:
Special care is required when you are not feeling well, as the risk of heatstroke increases.
Note for the elderly:
Special care is required in elderly people as their temperature control function decreases.

[The rainy season begins in Amami] Later than southern Kyushu, wary of heavy rain early in the rainy season

2025/05/19 12:35

Today, the 19th (Monday), the Japan Meteorological Agency announced that the Amami region is "presumably the rainy season has begun."
In the Amami region, the rainy season is seven days later than usual and two days earlier than last year.




This is the first time in six years since 2019 that the rainy season has entered before Okinawa.
On the 16th of this month, the rainy season began in southern Kyushu, ahead of the Okinawa and Amami regions, the earliest in the country.

The Amami region is cloudy and rainy due to the rainy season front.

The rainy season front and the humid air are expected to be cloudy and rainy for the next week.



#Warning for heavy rain early in the rainy season
The rainy season front passes from the East China Sea through the Amami region and extends east to Japan.
From tomorrow, the 20th (Tuesday), the front is expected to stagnate from the Amami region to the east of Japan.
The rainy season front will head north through the East China Sea, and a low pressure system will occur in the East China Sea on the front line.
The low pressure system is expected to progress to western Japan by the evening of the 21st (Wednesday).
World and humid air will flow towards the rainy season front and low pressure, and the Amami region will have a very unstable atmosphere.



In the Amami region, localized cumulonimbus clouds will develop locally over the 21st (Wednesday), causing heavy rain, and severe gusts of winds such as lightning strikes and tornadoes.
Also, if the rain clouds develop more than expected or stagnate in the same place, heavy rain will occur at an alarm level.
Please be careful of heavy rain early in the rainy season.

The rainy season is a seasonal phenomenon, and on average there is a period of "changes" of about five days after its inception.
Weather information regarding the rainy season is released as a breaking news based on the weather conditions up to now and the outlook for up to one week ahead.
Last day, the rainy season begins and ends will be comprehensively reviewed and confirmed.

Temperatures fall from the previous day in Kanto; some places are approaching midsummer day in western Japan

2025/05/19 06:43

Today, the 19th, the center of the high pressure system is expected to move to northern Japan. While many areas are in the sun, the sky is dominated by clouds in the Kanto region, and temperatures are expected to rise slowly.
The estimated maximum temperature is 20c in central Tokyo, 7c lower than the previous day. In addition, temperatures have slowed down on the Pacific Ocean side of Tohoku, where cold winds from the sea, and Sendai is expected to be 9 C lower than the previous day. Please do not get sick as the temperature difference from the previous day will be large.

/BOn the other hand, temperatures are rising in western and eastern Japan, where the sun is reaching, and temperatures are likely to rise for this time of year.
The estimated maximum temperature is 28c in Nagoya and Fukuoka, 27c in Osaka, and 26c in Kochi. In addition, in Toyooka, Hyogo Prefecture, it is expected to be 30 degrees Celsius and midsummer day.
This is still a time when your body is not used to the heat, so take proper measures against heat stroke, such as hydrating and replenishing your salt.

#Expected maximum temperatures in various regions (relevant season)
+Sapporo: 23c (as in late June)
+Sendai: 21c (as in normal)
+Tokyo: 20c (as in mid April)
+Niigata: 23c (as in normal)
+Nagoya: 28c (as in late June)
+Osaka: 27c (as in early June)
+Kochi: 26c (as in early June)
+Fukuoka: 28c (as in late June)

Weather for today, the 19th (Monday): There may be showers in the Kanto region. Beware of the increasing rain in the Nansei Islands

2025/05/19 05:55

Today, the rainy season front will move south on Sunday, the 19th, and is expected to stagnate south in Japan.



In the Kanto region, clouds are likely to spread throughout the day, with some areas where showers are likely to occur, mainly in the morning. When commuting to work or school, you can rest assured that you will have rain gear such as folding umbrellas. The weather is still fresh in the afternoon and it looks like it will be a day with little sunlight.

/BOn the other hand, from Hokkaido to Kyushu, there will be many areas where sunlight will reach the Sea of Japan side. Many places in Eastern to Western Japan are summer days, and some places are likely to be in the heat of midsummer day. Don't forget to take measures against heat stroke.
In Hokkaido, the weather may be uneven from night, so if you are late back, it is safe to have a folding umbrella.


Due to the influence of the front, the weather in the Nansei Islands is prone to rain. There is a risk of heavy rain or thunderstorms, especially in Amami, which is close to the front line. Be careful of landslides and flooding of rivers.

The atmosphere is unstable in southern Kyushu, Amami and Okinawa. Heavy rain warning!

2025/05/18 17:28

The rainy season front extends from the south of Shikoku to the south of Kyushu in the East China Sea.
The rainy season front will stagnate near the Tanegashima and Yakushima regions tomorrow, the 19th, and is expected to gradually move south to the Amami region on the 20th.


Warm and humid air flows towards this rainy season front, making the atmosphere extremely unstable from southern Kyushu to Amami and Okinawa.
Currently, heavy rain warnings and flood warnings have been issued in the northern part of Okinawa Prefecture's main island.



Cumulus clouds will develop locally in Kagoshima and Amami regions over the 20th, with severe gusts of winds such as lightning strikes and tornadoes.
Beware of heavy gusts of wind such as lightning strikes and tornadoes, and sudden heavy rain.


Please be careful of lightning strikes, gusts of wind and sudden heavy rain until the night of the 18th in the central and southern parts of Okinawa's main island.


[Rain commentary]
Precipitation from the beginning of falling (00:00 on the 18th) to 4:00 on the 18th (preliminary estimate from Amedas)
Okinawa Kunigami Murahiji 128.5 mm

[Rain forecast]
The expected 1 hour precipitation on the 18th is high,
Okinawa Northern Main Island 30 mm

The expected 24 hour precipitation from 6:00 on the 18th to 6:00 on the 19th is high,
The expected 24 hour precipitation from 6:00 on the 18th to 6:00 on the 19th is high,
The expected 24 hour precipitation from 6:00 on the 18th to 6:00 on the 19th is high,
The northern part of the main island is 80 mm

[Disaster prevention matters]
In the northern part of the main island, beware of landslides, rising rivers and flooding until the beginning of the evening of the 18th, and be careful of low-lying land flooding.
In the central and northern parts of the main island, beware of lightning strikes, gusts of wind and sudden heavy rain under the cumulonimbus clouds that have developed until the night of the 18th.
Be careful of heavy gusts of winds such as lightning strikes and tornadoes and sudden heavy rain in Kagoshima and Amami regions.

If there are signs of developing cumulonimbus clouds approaching, try to ensure safety by moving inside the building.

Kagoshima Prefecture: Be careful of landslides caused by heavy rain, flooding of low land, and rising rivers.

2025/05/18 08:34

Looking at the radar, you can see that there is a very strong precipitation area extending onto the line near Tanegashima.


The rainy season front has stagnated near southern Kyushu, and the atmosphere is becoming unstable due to the influence of warm, humid air flowing towards the front.


In the Satsuma and Osumi regions, heavy rain with lightning was poured locally on the morning of the 18th, and in the Tanegashima and Yakushima regions, extremely heavy rain or heavy rain with lightning was poured locally on the afternoon of the 19th, leading to heavy rain.
If the rain clouds develop more than expected or if heavy rain continues in the same location, a heavy rain warning or flood warning may be issued.

#Rain forecast
There is a high hourly rainfall expected on the 18th,
Satsuma region: 40mm
Osumi region: 40mm
Osumi region: 40mm
Osumi region: 50mm

Osumi region: 50mm


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Today, the 18th (Sunday) Kanto region, the heat is approaching 30 C during the day, so be careful of heat stroke

2025/05/18 08:04

The front is stagnant near Honshu.
In the Izu Islands, the weather will be affected by the front, and rain and stopping. Heavy rain is expected to occur locally with lightning. Be careful of landslides, lightning strikes, gusts of wind, etc.

In the Kanto region, although there are many clouds due to the effects of fronts and humid air, there are still sunny days, and temperatures are expected to rise to nearly 30 C during the day. Inland areas may be midsummer days above 30 C. It's a hot and humid day, so if you're staying outdoors, try to stay hydrated frequently to avoid heat stroke. Even if you are staying indoors, don't bear it and use air conditioning or a fan.



The atmosphere will be unstable in the evening, and thunderclouds will likely develop inland areas in the north. There are likely to be some short showers and thunderstorms around the evening. It would be best to bring a folding umbrella with you when you go out.

Tomorrow, Sunday the 18th, it's hot and humid with lots of clouds. In Kanto, even during midsummer days, heat stroke is a must

2025/05/17 18:04

There is a low pressure system in the Sea of Japan and it travels northeast.
The warm front extending from the center runs through the Hokuriku and Kanto to the southeastern sea of Kanto, while the cold front passes through the Chugoku, Shikoku and Kyushu regions to the East China Sea.
Currently, rain is falling on the Pacific side of northern and eastern Japan and western Japan.
It rained nationwide today.



Rain clouds are gradually moving eastward, and it is expected that more and more rain in northern Japan, east and western Japan will gradually stop.



Tomorrow, Sunday, May 18th, the rainy season front will be stagnant on the south shore of Honshu.
In western and eastern Japan, rain is in southern Kyushu, where the rainy season begins, and in other regions, there are many clouds due to the influence of fronts and humid air, but the temperature and humidity are high due to the sun's long enough to reach, making it likely to become humid and humid.
There may be some places, especially inland in the Kanto region, where temperatures are over 30 C.
This is a time when we are not used to the heat, and if we are outdoors, it may cause heat stroke.
Please be careful about your health.



In addition, in eastern Japan, showers may occur mainly in the afternoon, so when going out, it's safe to have a folding umbrella just in case.

/BPlease note that as the front is moving slightly south, there may be an announcement that the rainy season will begin in the Amami region, which is late in the rainy season.


In northern Japan, the weather will gradually improve and many areas will be sunny in the afternoon.
There are sunny days in the Okinawa region, but the atmosphere is temporarily unstable, so there are likely some areas where showers will fall.

The rainy season begins in southern Kyushu, first in statistical history. Southern Kyushu is the earliest in the country to begin rainy season, wary of heavy rain early in the rainy season

2025/05/16 12:34

Today, the 16th (Friday), the Japan Meteorological Agency announced that the southern Kyushu region is "presumably the rainy season has begun."
The rainy season has started on the 14th, and the 23rd earlier than usual.
Not yet announced that the rainy season will begin in Okinawa and Amami, and this is the first time that southern Kyushu will enter the country since statistics began in 1951.




Due to the rainy season front, the weather in southern Kyushu is cloudy and rainy.
We are expected to see more and more cloudy and rainy days over the next week due to the rainy season front and the humid air.
For this reason, it is expected that southern Kyushu will begin today, Friday, May 16th.



#Warning for heavy rain early in the rainy season
The rainy season front will extend to Kyushu tomorrow, Saturday, the 17th, and will stagnate in southern Kyushu tomorrow, Sunday, the 18th.
Words warm and humid air will flow towards the rainy season front, making the atmosphere very unstable in southern Kyushu.
In southern Kyushu, local cumulonimbus clouds will develop locally from the evening of the 16th (Friday) to the afternoon of the 18th (Sunday), and locally heavy rain will fall, causing severe gusts of winds such as lightning strikes and tornadoes.
Also, if the rain clouds develop more than expected or stagnate in the same place, heavy rain will occur at an alarm level.
Please be careful of heavy rain early in the rainy season.



The rainy season is a seasonal phenomenon, and on average there is a period of "change" of about five days after its inception.
Weather information regarding the rainy season is released as a breaking news based on the weather conditions up to now and the outlook for up to one week ahead.
Last time, the start of the rainy season and the end of the rainy season will be comprehensively considered and confirmed.