Atmospheric conditions are unstable from northern Japan to Hokuriku; storms are feared along the coast of northern Japan; rain continues in Okinawa

2026/05/09 12:06

Two low pressure systems are moving near Hokkaido today, the 9th (Saturday). One is passing near Hokkaido, and the other is expected to move northeastward, accompanied by a front, and continue to develop near the Kuril Islands.

Low pressure systems are accompanied by strong cold air in the upper atmosphere, causing unstable atmospheric conditions mainly on the Sea of Japan side from northern Japan to Hokuriku. In addition, winds are increasing, especially along the coasts of northern Japan, and storm warnings have been issued in some places.



On the Sea of Japan side from Hokuriku to Tohoku, please be careful of sudden rain and thunderstorms even after the rain has stopped. Depending on the degree of development of rain clouds, severe phenomena such as lightning, tornadoes, strong gusts of wind, and hail may occur, so please be aware of changes in the sky pattern. Thunderclouds are expected to develop easily in some parts of the inland areas of the northern Kanto region, so please be careful of sudden changes in the weather.
Also, because the spacing between the isobar lines is narrow, there is a risk of extremely strong winds blowing mainly along the coast of northern Japan. In coastal areas of the Tohoku region, maximum instantaneous wind speeds are expected to reach 30 meters, so please be careful of strong winds and high waves, and be aware of the impact on traffic.



It seems that there will be some snow in Hokkaido due to the cold air above. The area of rain and snow is expected to gradually narrow into the evening, but please be careful of deteriorating road conditions in inland areas and along the mountains of northern Hokkaido.



In Okinawa, rain will continue throughout the day due to the rainy season front. There is a risk of localized heavy rain accompanied by lightning, so please be careful of landslides and flooding of low-lying areas.

Storm warning for northern Japan; caution for heavy rain, landslides, flooding, and rising water in Okinawa region

2026/05/09 10:52

There is a low pressure system over the west and east coasts of Hokkaido, and it is moving northeast.
The front is extending from the low pressure area over the eastern seaboard to the southern coast of Japan, and the rainy season front is stationary near Okinawa.
On the other hand, there is an anticyclone in the East China Sea that is spreading toward western Japan.






Currently, it is raining from Hokkaido and Tohoku to the Sea of Japan side of the Hokuriku region, as well as the Amami and Okinawa regions, and storm warnings have been issued in some areas of Hokkaido and Tohoku.

Today, it is expected to be sunny from Kanto to Kyushu due to high pressure,
There will be many places in Hokkaido where it will rain, and there will be places in Tohoku and Hokuriku where there will be rain and thunderstorms until around noon.
Towards the evening, stormy winds are expected to blow from the west due to the developing low pressure system.
If you are on land on the Pacific side of Tohoku, please be careful of traffic disruption and damage to buildings due to strong winds.
If the atmospheric pressure gradient becomes larger than expected, warning-level winds from the west may occur over the sea off the Pacific coast of Tohoku and on land along the Sea of Japan side of Tohoku.





Also, due to the influence of the front, the atmospheric conditions in the Okinawa region will be extremely unstable, and it will rain intermittently.
Depending on the degree of rain cloud development, there is a risk of heavy rain reaching warning level.
Please be careful of landslides, flooding of low-lying areas, and rising river waters.
In the Daitojima region, please be careful of lightning, tornadoes, strong gusts of wind, and sudden heavy rain.

###Wind forecast
Maximum wind speed (maximum instantaneous wind speed) expected on the 9th
Tohoku Sea of Japan side, land 15 meters (30 meters)
Tohoku Pacific side, sea 18 meters (30 meters) meters)
Tohoku Pacific side land 18 meters (30 meters)

###Rain forecast
The predicted 1-hour rainfall on the 9th is high in places
Okinawa main island region 30 mm
Miyakojima region: 30 mm
Yaeyama region: 30 mm

The predicted 24-hour precipitation from 6:00 on the 9th to 6:00 on the 10th is high
Okinawa main island region: 60 mm
Miyakojima region 60mm
Yaeyama region 60mm

###Disaster prevention matters
On land on the Pacific side of the Tohoku region, please be on guard against traffic disruptions and damage to buildings from the morning of the 9th into the evening due to storms from the west.
Also, please be careful of traffic obstructions and damage to buildings due to strong winds from the west, both on the sea on the Pacific coast of Tohoku and on land on the Sea of Japan side of Tohoku.

In the main island of Okinawa and the Sakishima Islands, heavy rain is expected to occur in some places on the 9th.
Depending on the degree of rain cloud development, there is a risk of heavy rain on the 9th.
Please be careful of landslides, flooding of low-lying areas, and rising river waters.
In the Daitojima region, please be careful of lightning, tornadoes, strong gusts of wind, and sudden heavy rain on the 9th.
If there are signs that a cumulonimbus cloud is approaching, please take precautions such as moving inside a building.
Okinawa Main Island and Sakishima Islands also need to be careful about lightning and gusty winds under the developed cumulonimbus clouds on the 9th.

Warning-level heavy rain is expected in Okinawa until the 10th (Sunday); beware of heavy rain disasters

2026/05/08 17:25

The rainy season front extends from southern China to the Nansei Islands, and rain clouds accompanying the front are forming near the Nansei Islands.
On Kesa, active rain clouds passed over the Okinawa region, and heavy rain of 41.0 mm/h was observed on Yonaguni Island, Okinawa Prefecture.



The Okinawa region is likely to be affected by the seasonal rain front from now until the 10th (Sunday), and atmospheric conditions are expected to become extremely unstable.

In the main island of Okinawa and the Sakishima Islands, heavy rain is expected to fall in some places in excess of 30mm per hour into the morning of Saturday the 9th. Depending on the degree of rain cloud development, there is a risk of heavy rainfall in the Sakishima Islands until the 9th (Saturday) tomorrow, and in the main island of Okinawa until the 10th (Sunday).
Please be careful about landslides, flooding of low-lying areas, and rising river waters.

In the Okinawa main island region and Daitojima region, please be careful of strong gusts such as lightning and tornadoes through tomorrow, the 9th (Saturday). If there are signs that a developed cumulonimbus cloud is approaching, please try to ensure your own safety by moving to a sturdy building. Even on the Sakishima Islands, caution is required as there is a risk of lightning strikes and gusts of wind under developed cumulonimbus clouds.

#Expected amount of rain (in places where there is a lot)
+1-hour precipitation expected for today 8th
Miyakojima region 30mm
Yaeyama region 30mm
+1-hour precipitation expected for tomorrow 9th (Saturday)
Okinawa main island region 30 mm
Miyakojima region 30mm
Yaeyama region 30mm
+Forecasted by the evening of tomorrow 9th (Sat) 24 hour precipitation
Okinawa main island region 80mm
Miyakojima region 80mm
Yaeyama region 80mm

[Beware of sudden changes in weather] Thunderstorms and heavy rain will continue until tomorrow in northern Japan; next week will be even hotter (commentary: weather forecaster Atsuko Miyake)

2026/05/08 14:18

The weather looks like it's going to change suddenly this afternoon.
Please pay attention to changes in the sky.



First, here is a look at the rain clouds at noon.

A low-pressure system with cold air is approaching in the sky, and heavy rain is occurring in some areas, especially in Hokkaido and Hokuriku.

Also, active rain clouds are approaching near the Nansei Islands due to the seasonal rain front.
After this, it is expected to affect the Amami region and the main island of Okinawa.



Let's take a look at the rain clouds after this.
In the evening, the rain is likely to become heavier in the Kanto and Tokai regions.

In addition, there is a risk of violent tremors accompanied by thunder in the Okinawa region from evening onwards.
Please be careful of localized heavy rain.

There is a risk of rain and thunderstorms from the Kanto region to the Hokkaido region late into the evening.

Please be careful of localized sudden and strong rain, lightning,
gusty winds, and hail.

If you hear thunder, move to a sturdy building.



Looking at the forecast weather map for tomorrow,
the cold air in the upper atmosphere is expected to gradually disappear, and
will be covered by high pressure from the west.

For this reason, there are still some places where the wind is strong during the day, but
the wind is likely to weaken in many places at night.

It looks like there will be many sunny days around Honshu.

Meanwhile, the rainy season front will remain stationary near Okinawa, so it looks like the rainy season will continue tomorrow.



Let's take a closer look at the weather ahead.
In Sapporo, where the tomorrow rain symbol is marked, it will probably last until around noon.
Even in the Hokuriku region, the rain is expected to stop and the weather will improve around noon.

Saturday and Sunday, many places will be sunny during the day
It looks like it will be a sunny weather typical of this time of year.
There is a big difference in temperature between morning and evening and during the day, so
Please wear clothes that are easy to put on and take off.

It looks like there will be many sunny days into the second half of next week.
Temperatures will continue to rise towards the end of next week.
It looks like there will be days when the temperature approaches 30 degrees Celsius, so it's time to take measures against heatstroke.

And it will continue to rain in Naha until the middle of next week.
Please note that there are days when it rains more heavily, so please check the latest information.

[First time event! Early Summer Lake Biwa Fireworks] Symphonic Star Mine 2026 What will the weather be like tomorrow night (Commentary: Weather forecaster Junko Miyake)

2026/05/08 14:04

Fireworks season has already begun in the Kinki region.
There will be a fireworks display at Lake Biwa on the night of Saturday, May 9th tomorrow.



"Symphonic Star Mine 2026" will be held for the first time this year.

As the name suggests, this fireworks festival is a live art festival where music (live music) and fireworks are perfectly synchronized.

The event will be held on Saturday, May 9th from 7:30pm to 8:30pm, and will be held on the Karasuma Peninsula on the shores of Lake Biwa.



The weather is interesting.

Looking at the forecast weather map for tomorrow,
it is expected to be gradually covered by high pressure during the day.

The area around Lake Biwa will be sunny and sunny during the day.

The wind will still blow strongly during the day tomorrow, but
the wind will weaken at night.

The wind is expected to weaken around the time of the fireworks, so
I think it will be a good day for fireworks.



Let's take a look at the weather and temperature around the Karasuma Peninsula in chronological order, where tomorrow's Symphonic Star Mine will be held.

Tomorrow's daytime is expected to be sunny and the temperature will rise to around 23 degrees Celsius by around 3pm.

I get sweaty when I move a little, so short sleeves are probably a good idea during the day.

The temperature drops at night, and the temperature around the time of the fireworks is expected to be around 15c to 16c.

The wind will be a little weaker, but it will still be from the north, so it might be a good idea to bring an extra layer.



Where you view fireworks is very important.
The wind will blow from the northwest tomorrow, so there is a possibility that the area around the Karasuma Peninsula, the main venue, will be on the leeward side.

It might be a good idea to look a little further away from the main venue
, especially from the windward side.

Please refer to this and enjoy the fireworks.

Weather for today, the 8th (Friday): Widespread rain due to low pressure moving over the Sea of Japan. Be careful of thunderstorms.

2026/05/08 07:44

Today, the 8th (Friday), due to the influence of a low pressure system moving northeast over the Sea of Japan, rain will fall over a wide area, mainly on the Sea of Japan side of northern and western Japan. In Okinawa and Amami, the weather is expected to be prone to rain again due to the influence of the rainy season front.



Due to the influence of a low pressure system moving northeast over the Sea of Japan, rain is expected to fall over a wide area, mainly on the Sea of Japan side of northern and western Japan. In northern Japan and the Hokuriku region, there are likely to be places where it will rain with localized thunder.

Clouds are expected to spread easily in the Kanto region as well. Atmospheric conditions are expected to be extremely unstable, mainly in the northern Kanto region, from early afternoon to late evening today, the 8th (Friday), due to cold and humid air in the upper atmosphere. Please be aware of changes in the sky and be on the lookout for lightning, tornadoes, strong wind gusts, sudden heavy rain, and hail.

Western Japan will initially be cloudy, but the sun will gradually return in the afternoon.

It will be rainy in Okinawa and Amami due to the rainy season front. In the Okinawa region, heavy rain is expected to occur in some places, accompanied by localized thunderstorms.



Temperatures are expected to be around or above normal in many places, with Sendai expected to reach 23 C, similar to mid-June, and Tokyo, 27 C, similar to late June.
Even under cloudy skies, don't forget to take precautions against heat stroke, such as staying hydrated frequently.

Due to the influence of a developing low pressure system, barges are widespread from the south of Japan to the east of Japan [Marine summary (April 26, 2026 - May 2, 2026)]

2026/05/07 23:39

From April 30th to May 2nd, a low pressure system accompanied by a front passed from the East China Sea near Japan and moved east of Japan. As a result of this, the waves increased, and on May 2nd, there was a storm over a wide area from the south of Japan to the east of Japan. Wave height reached 5m from the coast of Sanriku to the east of Kanto.

Below is a summary of the ocean (April 26, 2026 - May 2, 2026).



#Pressure distribution and waves
On the 26th, a front stalled from south of Okinawa to south of Japan to east of Japan. A rather strong easterly wind was blowing north of the front, and the waves were rising.
On the 27th and 28th, a low pressure system formed above the front, developing and moving far east of Japan. Waves were rising in the east of Japan.
On the 29th, a low pressure system moved eastward east of Japan. Waves rose in the eastern Kanto region.
From May 30th to May 2nd, a low pressure system accompanied by a front passed from the East China Sea near Japan and moved east of Japan. There was a large gradient in pressure around the low pressure system and the front, and winds became stronger, and waves rose in the East China Sea on the 30th and in the south and east of Japan from May 1 to 2. On the 2nd, a storm spread over a wide area from southern Japan to eastern Japan.



#Sea surface temperature
Sea surface temperatures in the Japanese waters continue to be higher than normal in the northern and central regions.
The sea area continued to be significantly higher than normal in the western part of the country, with temperatures up to 4c higher than normal.
The East China Sea was at normal levels, and the waters near the Nansei Islands, which are slightly higher than normal, have shrunk.
South of Japan, sea areas continued to be slightly higher than normal.
The waters off the coast of the Tokai region were at normal levels, and waters slightly higher than normal continued from the south of Kanto to the east of Kanto.
Off the coast of Sanriku, the sea area continued to be significantly lower than normal, with temperatures up to 4 C lower.
The waters around the Chishima Islands and the Sea of Okhotsk continued to be at normal levels.

[Weekly Weather] Beware of thunderstorms north of Kanto tomorrow! After that, sunlight prevails (commentary: weather forecaster Atsuko Miyake)

2026/05/07 13:36

Today, the 7th (Thursday) after the holidays, many places are sunny.
Okinawa, which recently entered the rainy season, is now experiencing a sunny spell during the rainy season.



The temperature is rising in many places due to this sunshine.
In Kamioka, Hida City, Gifu Prefecture, the temperature was 29.2c by noon, approaching the height of midsummer.

Temperatures are also rising in the Tohoku region, with
Shizugawa, Miyagi Prefecture recording the hottest temperature of the year at 28.0c.
Tokyo also experienced summer for the first time in three days at 25.1c.



Today, the 7th (Thursday), the temperature is likely to rise even further.
Looking at the weather and predicted maximum temperature for today, the 7th (Thursday),
Yamagata, Fukushima, and Kofu are also expected to reach 29c.
Even in the Tohoku region, it will be as hot as a midsummer day.
The temperature difference from yesterday will be large in some places, so
Please take good care of your physical condition.



And tomorrow, the 8th (Friday), a low pressure system will form in the Sea of Japan and off the coast of Sanriku.

As there is cold air above this low pressure system,
atmospheric conditions are expected to become unstable mainly in eastern and northern Japan near the low pressure system.



Let's take a look at the rain forecast for tomorrow, the 8th (Friday).

If you check the forecast from 9:00 a.m. on Friday the 8th,
it looks like there will be rain in the
morning from Hokkaido and Hokuriku to the Kinki region, where
the low pressure system is approaching.

In the afternoon, rain is expected to begin in the Tohoku and Kanto regions.
There is also a risk of heavy rain accompanied by thunder.
Especially at night,
east and northern Japan should be careful of sudden heavy rain, lightning,
gusty winds, and hail.



The rain tomorrow, the 8th (Friday), will mostly stop by the morning of the 9th (Saturday).
It looks like it will be sunny in many places during the day on Saturday and Sunday.
From now on, there will be many sunny days
During the day, the temperature will rise to around 25c.
There is a large difference in temperature between morning and evening and during the day, so please be sure to dress accordingly.


In Okinawa and Amami, where the rainy season has begun, it is likely that rain will continue into the middle of next week.

Tomorrow night, the atmosphere will be unstable in northern Japan and northern Kanto; watch out for sudden thunderstorms

2026/05/07 12:20

Towards the evening of today, the 7th, two low-pressure systems located in the sea near the Chishima Islands and in the western Sea of Japan,
and a front extending from east to west near the Izu Islands are expected to approach Japan.



On the 8th tomorrow, a low pressure system in the western Japan Sea is expected to move toward Hokkaido, and another low pressure system is expected to form off the coast of Sanriku.
As a result of this, winds will blow southerly around Japan, making it easier for warm, humid air to flow towards
fronts and low pressure systems.



Meanwhile, strong cold air for this time of year is expected to move southward in the sky, mainly over northern Japan.
The presence of warm, humid air near the ground and strong cold air above will make the atmosphere extremely unstable, making it likely that cumulonimbus clouds will develop rapidly.
Please be careful of sudden changes in weather.






If you feel the following changes, it is a sign that a cumulonimbus cloud is approaching.
#The sky has suddenly become dark
#The wind has suddenly become cold
#I can hear thunder, etc.
Please evacuate to a safe building immediately.

Weather for the week: Rain and thunderstorms on the 8th (Friday) mainly on the Sea of Japan side; rainy season continues in Okinawa, so be careful about how it rains

2026/05/06 20:04

From now on, it is likely to rain on the 8th (Friday) in the second half of the week, mainly on the Sea of Japan side. From the 10th (Sunday) onwards, there will be many sunny days around Honshu, but Okinawa will continue to experience rainy weather.



From the 8th (Friday) to the 9th (Saturday), a trough or low pressure system will pass near northern Japan. The atmospheric conditions will be unstable due to the influence of cold air in the upper atmosphere, and rain and thunderstorms will occur mainly in areas along the Sea of Japan, such as Hokkaido, Tohoku, and Hokuriku. Please be aware of changes in the sky as there is a possibility of heavy rain, thunderstorms, tornadoes, and strong wind gusts occurring in a short period of time. Also, even in areas where there is no rain symbol in the weather forecast, there is a possibility of showers or thunderstorms, so it is a good idea to bring a foldable umbrella when going out.

After the weekend, the 10th (Sunday), there will be many sunny days around Honshu. However, around the 12th (Tuesday), there may be rain and thunderstorms in some inland areas due to the influence of cold air in the upper atmosphere. There are some places where the temperature during the day can reach over 25 degrees Celsius, but the difference in temperature between morning and afternoon tends to be large, so please dress accordingly and stay in shape.

Okinawa/Amami has many rainy days, and the rainy season will continue. The front is likely to stagnate, and the center of low pressure is expected to pass through frequently. There is a risk of severe thunderstorms occurring when the center of the low pressure system passes through, so you need to be careful about how the rain falls.
Typhoon No. 5 occurred in the Caroline Islands on Thursday the 6th. The typhoon is expected to move westward and have no direct impact on areas near Japan, but there is a risk that moist air from the typhoon will flow into areas near Okinawa, leading to increased front activity. Please pay attention to future weather information.