Weather for the week: High temperatures near Honshu, unstable and changeable weather; Okinawa is closed during the rainy season

2026/05/11 07:36

From now on, there will be many days when the area around Honshu will be covered by high pressure, and temperatures will be higher than average nationwide. The maximum daytime temperature will be around 25 degrees Celsius, and temperatures are likely to trend upward into the second half of the week.



On the weekend, there may be some places where the daytime maximum temperature is 30c. The predicted maximum temperature in Nagoya and Osaka on Sunday the 17th is 29 degrees Celsius, one step before midsummer day, in Kofu it is expected to be 31 degrees Celsius, and in Takayama City, Gifu Prefecture, it is expected to be 30 degrees Celsius.
Summer hasn't really started yet, but please be careful not to get heatstroke. It is best to take precautions such as hydrating frequently, taking appropriate breaks, and turning on the air conditioner indoors rather than holding back.

In addition to the rise in daytime temperatures, cold air frequently flows into the skies near Honshu, so there will be many days when the atmospheric conditions will be unstable, especially inland and along the mountains. From tomorrow, the 12th (Tuesday), there may be localized rain and thunderstorms in inland Honshu due to the influence of cold air in the upper atmosphere. Even if there is no umbrella symbol in the weather forecast, be careful of sudden rain or thunderstorms in the afternoon. Depending on the degree of development of rain clouds, severe phenomena such as lightning strikes and gusts of wind may occur, so it is necessary to pay attention to changes in the sky pattern.

The rainy season front will gradually move far south of Japan, so there will be many relatively sunny days in Okinawa and Amami. It looks like it will be a break during the precious rainy season.

Today's weather (Monday 11th): Clear skies around Honshu; watch out for sudden rain and thunderstorms inland and along the mountains in the afternoon

2026/05/11 07:08

Today, the 11th (Monday), the end of the week, the area around Honshu will continue to be within the area of high pressure. Meanwhile, the rainy season front remains stationary in the south of Japan.

It will be bright and sunny in many areas around Honshu. The maximum temperature during the day is expected to be around 25c in many places, so it will be a sunny day without the need for a jacket. In inland areas, the temperature difference between morning and afternoon tends to be large, so be sure to dress appropriately and stay in shape.



However, in the afternoon, atmospheric conditions will be unstable mainly in inland areas and along the mountains of eastern Japan due to the influence of cold air in the upper atmosphere. In inland areas such as southern Tohoku and northern Kanto, there is a high probability of lightning occurring, and thunderclouds are likely to develop and the weather may change suddenly. Even if there is no umbrella symbol in the weather forecast, be careful of sudden rain or thunderstorms.



Okinawa and the Ogasawara Islands will likely have a rainy day due to the influence of the rainy season front. There is a risk of localized heavy rain accompanied by thunder, so please be careful of flooding of low-lying areas, landslides, and rising river waters.

Tomorrow 11th (Monday) Kanto region: Sunny mark, but beware of showers

2026/05/10 17:58

The high pressure system that brought sunshine to Honshu today will move away to the east of Japan from tonight onwards.
Tomorrow, the 11th (Monday), there will be active rain clouds over Okinawa and the Ogasawara Islands, which are affected by the rainy season front, but sunshine is expected to reach a wide area from northern Japan to western Japan.



The weather mark says it's sunny, but we can't let our guard down in the Kanto region.
It will enter the rear of the high pressure system, bringing in warm and humid air with southerly winds, and in addition to that, the upper atmosphere is expected to have cold air moving southward for this time of year.





As a result, atmospheric conditions will become unstable, and the probability of lightning strikes will continue to be high, especially in the afternoon. There is a possibility of localized light showers.



This week, the temperature difference between the sky and the ground will increase, and the atmospheric conditions will continue to be unstable, so it's a good idea to carry a folding umbrella in your bag to avoid getting wet in the sudden rain.

There is a risk of heavy rain in the Ogasawara Islands from tonight until late tomorrow night on the 11th. Be careful of landslides and rising river waters.

2026/05/10 12:17

Currently, there is a front in the south of Japan, extending east-west from the Nansei Islands to the Ogasawara Islands.
Atmospheric conditions in the Ogasawara Islands are expected to become unstable until tomorrow, the 11th (Monday), as warm, humid air flows towards the front. It will rain intermittently, and there will be periods when the rain becomes heavier and may be accompanied by thunder.



Please be careful of landslides in the Ogasawara Islands from early evening today, the 10th (Sunday) to late evening on the 11th (Monday) tomorrow.
Also, please be aware of rising river water levels until noon today, the 10th (Sunday).

If the rain clouds develop more than expected, or if the developed rain clouds continue to cover the area, there is a possibility of warning-level heavy rain.



From early morning until dawn on the 11th (Monday), there will be heavy rain accompanied by thunder in some places.

[Rain Forecast]
Expected 1-hour precipitation today, the 10th (Sunday), is expected to be high in some places,
Ogasawara Islands 20 mm
tomorrow, the 11th (Monday). The predicted 24-hour precipitation from 6:00 a.m. on the 10th (Sunday) to 6:00 a.m. on the 11th is high in the Ogasawara Islands.
Ogasawara Islands 80mm
Then, the predicted 24-hour precipitation from 6:00 on the 11th to 6:00 on the 12th will be high,
Ogasawara Islands 60mm

[Disaster prevention matters]
Please be careful of landslides in the Ogasawara Islands from early evening today, the 10th (Sunday) to late evening tomorrow, the 11th (Monday).
Please be careful of rising river water levels until noon today, the 10th (Sunday).

Today's weather on the 10th (Sunday): Great weather for going out in a wide area; rainy skies continue in the Nansei Islands

2026/05/10 06:46

On Mother's Day, the 10th (Sunday), the area around Japan will be covered by a migratory high pressure system. Therefore, it looks like it will be a day where you can enjoy a wide range of outings. Meanwhile, the rainy season is expected to continue in the Nansei Islands.



In Hokkaido, clouds are expected to remain on the Sea of Okhotsk side until morning, but the weather will gradually improve and the blue sky will spread throughout the day.
The weather will not deteriorate from Tohoku to Kyushu, and it looks like it will be a calm day. The weather will be fine for going out.

During the day, there are many places where the temperature is typical of this time of year, and there are some places where it can be so hot that you sweat a little when you move during the day. It gets colder in the morning, so the temperature difference between morning and evening and daytime increases. Please take care of the temperature difference by adjusting your clothing.

Meanwhile, the rainy season continues in the Nansei Islands. It will be a cloudy and rainy day, and the weather will not be refreshing. It's safe to have rain gear when going out.

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.