[Marine summary] Typhoon No. 4 near Ogasawara, large seas around the typhoon Sea surface temperature continues to be significantly lower than normal off the coast of Sanriku (April 19th to 25th, 2026)

2026/04/28 11:28

Typhoon No. 4 moved northeast through the waters near Ogasawara, creating a huge storm around the typhoon, with waves reaching a maximum height of 7 meters.
Sea surface temperatures off the coast of Sanriku continued to be significantly lower than normal.
Below is a summary of the ocean (April 19-25, 2026)



#Pressure distribution and waves
On the 19th, Typhoon No. 4 moved northeast through the waters near Ogasawara.
Waves were rising on the Pacific side, and a barge broke out near Ogasawara.
The area around the typhoon was flooded with waves, with maximum wave height reaching 7m.
On the 20th, the typhoon turned into an extratropical cyclone near Minamitorishima, and high waves continued in the east of Japan.
On the 21st, waves rose in the waters around Hokkaido due to the effects of low pressure to the southeast and west of Hokkaido.
On the 22nd, a low-pressure system became stationary near Primorye, and waves rose in the central and northern parts of the Sea of Japan.
On the 24th and 25th, a low pressure system accompanied by a front moved from east of Japan to the east of the Kuril Islands, and waves rose from south of Japan to east of Japan.
On the 25th, a low pressure system became stationary in the south of Japan, and a low pressure system formed in the south of Japan around the low pressure system.



#Sea surface temperature
Sea surface temperatures in the Japanese waters were significantly higher than normal, and were up to 4 C higher than normal on the western continental side.
However, the fairly high sea area gradually shrank.
The East China Sea was at normal levels, and waters near the Nansei Islands and south of Japan continued to be slightly higher than normal.
The sea off the coast of the Tokai region was at normal levels, and temperatures from the south of Kanto to the east of Kanto continued to be slightly higher than normal.
Off the coast of Sanriku, the sea area continued to be significantly lower than normal, with temperatures up to 4 C lower.
The sea near Chishima Island and the Sea of Okhotsk continued to be at normal levels, and the sea ice area decreased.

Weather for the week: Low pressure and fronts passing one after another. Widespread rain and stormy weather possible from 30th to 1st.

2026/04/28 07:10

From here on, low pressure systems and fronts often pass near Honshu. From the 30th to the 1st of the month, there is a risk of strong rain and wind due to the influence of a developing low pressure system.



Tomorrow, the 29th (Tuesday), the area around Honshu is expected to be in a high pressure area, but clouds will likely spread more easily. Rain clouds from a low-pressure system accompanied by a front will approach from the west, and the weather will turn downhill in southern Kyushu and the Nansei Islands.

From the 30th to the 1st, a low pressure system is likely to develop and advance near the southern coast of Honshu. It will rain widely from Kyushu to Tohoku, and due to the influence of warm, humid air moving toward the front, the rain will become heavier in some places on the Pacific side of western and eastern Japan. Additionally, as the low pressure system develops, the distance between the isobar lines will narrow, so not only will there be more rain, but the wind will also become stronger, and the weather is likely to be rough. Please pay attention to the latest weather information.

Around the 2nd, after the low pressure system leaves east of Japan, the weather will improve in many places, but the next front and low pressure system are likely to approach. At present, there is a wide range of forecasts and uncertainties regarding the extent of the rain, the timing of its onset, and the strength of the rain, but if you are planning to go out during Golden Week, please check the weather forecast frequently.

From now on, some places will have sunny days with temperatures above 25c. However, there are likely to be days when the temperature drops below 20c on rainy days, and the daily temperature changes are likely to be large. Please dress appropriately and make sure you don't get sick due to the temperature difference.

Weather forecast for today, the 28th (Tuesday): Summer weather forecast for Kanto and Tokai regions. Beware of rain and thunderstorms in Tohoku and Hokuriku from the afternoon.

2026/04/28 06:25

The low pressure system that brought rain to western and eastern Japan today, the 28th (Tuesday) and yesterday, the 27th, will move away. Meanwhile, another low pressure system will move through the Sea of Japan.

Eastern Japan is widely covered by high pressure, and the Kanto and Tokai regions are likely to see some places where the sun will reach them, causing temperatures to rise significantly compared to the previous day. The expected maximum temperature in Tokyo is 24c, and in Nagoya it will be 25c, and it will be a summer day in some places.

Meanwhile, a low pressure system moves across the Sea of Japan. From the afternoon onwards, the weather will turn downhill and rain will begin in Tohoku and Hokuriku. When going out, it's a good idea to take an umbrella with you even if it's not raining. In the Tohoku region, there is a possibility of localized thunderstorms with heavy rainfall over a short period of time, so please be careful of sudden changes in the weather. There are many clouds in Hokkaido, and there are likely to be places where the temperature will drop significantly compared to yesterday.

Clouds will gradually spread over western Japan, and there are likely to be localized showers in the evening. Even if there is no umbrella symbol in the weather forecast, it is a good idea to carry a foldable umbrella in case you will be returning home late.

[Seismic intensity 5+ in Hokkaido] How to prepare When does it rain in Hokkaido What should I be careful about (Commentary: Weather forecaster Atsuko Miyake)

2026/04/27 14:37

At dawn today, April 27th (Monday), there was a strong earthquake in Hokkaido with a seismic intensity of 5+.



The Japan Meteorological Agency has announced that it is not directly related to last week's Sanriku-Oki Earthquake, and that it does not apply to the Hokkaido Sanriku-Oki Later Earthquake Information.
However, we do not know when a major earthquake will occur in the future.



Let's prepare on a daily basis.
Let's check evacuation sites and routes on the
hazard map.
Please check with your whole family.
Also, be sure to stock up on disaster prevention supplies and be prepared
.
Are there any foods whose expiration dates have passed


Also, be sure to check your carry-out bag.
And how to contact your family.
Where should we meet in an emergency
How should we communicate It might be a good idea to start talking about this now.
Also, it is effective not only in earthquakes, but also in landslides caused by heavy rain,
, so it is better to sleep in clothes that allow you to escape quickly.
It is a good idea to keep an emergency bag next to your bedside so that you can quickly grab it and run away.



And from now on,
There is no forecast for rain over a wide area in the Hokkaido region.
Rain is expected in Kushiro on Saturday the 2nd,
as the low pressure system approaches, but
it is not expected to be that heavy.


What we need to be careful about from now on is the change in temperature.
Tomorrow, the 28th (Tuesday), the maximum temperature in Abashiri will be 5 degrees,
as cold as late March.
However, on the 11th (Friday), the temperature in Abashiri will rise to 18 degrees,
as warm as late June.
Please be careful not to get sick due to this difference in temperature
.

[Kanto/Sudden weather change] Will it start raining again in the evening There is a lot of rain during Golden Week, so pay attention to the latest information (commentary: weather forecaster Atsuko Miyake)

2026/04/27 13:58

The Kanto region experienced some clear skies before noon, but the weather will continue to change in the afternoon.
We need to be careful of sudden rain after this.



Looking at the state of the rain clouds as of noon,
rain clouds associated with a low pressure system are hanging over the Kanto, Tohoku, and Hokuriku regions at this time.
The rain is getting stronger in some places,

on the Pacific side of the Kanto and Tohoku regions,
more than 10mm of rain per hour has been observed.
Let's take a look at the rain clouds after this.



In the evening, rain clouds will again cover the Kanto region.
Active rain clouds have started to gather, and it looks like the rain will become heavier in the evening and into the night.
Even if it's raining now,
you can rest assured if you have rain gear for your next outing.
Late at night, rain clouds will pass through the Tohoku region, but
the Kanto region is likely to remain prone to rain until the date changes.

shows the forecasted weather map for tomorrow, the 28th (Tuesday).
Another low pressure system is approaching from the Sea of Japan and is expected to pass over the Tohoku region.



Tomorrow (Tuesday), it is expected to rain again from Tohoku to Hokuriku region.
Please bring an umbrella with you when you go out tomorrow.
It will continue to be rainy from now on through the Golden Week.




This year's Golden Week,
low pressure systems and fronts will be approaching one after another.
It looks like the rainy conditions will continue.
Especially from the 30th to the 31st, a
low pressure system will develop as it passes near Honshu.
Both rain and wind are expected to increase,
causing severe weather over a wide area.

Also, there is a risk of
warning-level heavy rain in western Japan and the Nansei Islands, so please pay attention to the latest information.
On Saturday the 2nd, it looks like there will be some sunshine across the country.
This day seems like Golden Week
You can feel the early summer heat.
lets you see detailed weather information for each location.




Today, the 27th (Monday), it will be rainy mainly from the Kanto region to the Tohoku region and
Hokuriku region.

In areas where it rains, the temperature does not rise
It seems to feel cool at around 15 to 18 degrees.
On the other hand, in western Japan, where the weather is sunny, the temperature is likely to rise to around 25 degrees, making it hot and sweaty.



Forecast for tomorrow (Tuesday).
The weather in the Kanto region is expected to improve
temperatures will rise to around 25 degrees.
It looks like tomorrow will be a cheerful day with short sleeves.
And let's take a look at the forecast for this past week.


From Thursday the 30th to Friday the 1st, there is a possibility that the rain will become heavier and the weather may become rough nationwide.
Please pay attention to the latest information when going out.



The possibility of clear skies is increasing from the 3rd (Sunday) onwards.
However, depending on the movement of the low pressure and front, there is still a possibility that the weather will turn into a
rain mark.
Please pay attention to the latest information.

Sunny skies will return tomorrow mainly in eastern Japan; watch out for showers in northern Japan

2026/04/27 12:42

Tomorrow, the weather in the Japanese archipelago is expected to turn around from today's rainy pattern, and the weather is expected to improve over a wide area. Particularly in eastern Japan, the weather has been sunny since the morning, and it looks like this will be the first day in a long time that we will be able to experience blue skies.



In Tokyo, the maximum temperature tomorrow is expected to be around 24c, and it will be so warm that you won't need a jacket during the day. Although the air remains humid due to today's rain, there will be plenty of sunlight, so your laundry will dry well even if you hang it outside. This is also the time when UV rays start to get stronger, so it is essential to take sun protection when going out.

Sunny days are expected to spread throughout western Japan, including Nagoya and Osaka, with temperatures expected to reach over 25c in some places. The weather can be sweaty and hot during the day, so you need to stay hydrated frequently when doing outdoor activities. Especially in Osaka, the humidity is high due to today's rain, and there will be times when it will feel hot and humid.



On the other hand, in Hokkaido and northern Tohoku, clouds are likely to spread due to the influence of a low pressure system moving eastward from the continent, and the sky is expected to be unclear. There is a chance of temporary rain mainly in the afternoon. It's safe to carry a folding umbrella when you go out.

Western and northern Japan are sunny and temperatures are rising; temperatures are not rising in the Kanto region and it is cool.

2026/04/27 06:45

It has been raining in the Kinki region and eastern Japan since the morning due to the influence of a low pressure system moving south of Honshu.



Today, the 27th, the low pressure system will move eastward, and western Japan will see clear skies and sunshine, and temperatures will rise. Hokkaido and the northern part of Tohoku also have periods of sunshine, and there are many places where the temperature will exceed 20 degrees Celsius, making it as sunny as mid-May, and in some places in Hokkaido, the temperature is likely to be similar to early June. You will feel comfortable during the day.

On the other hand, eastern Japan and Tohoku are expected to experience heavy rain and little sunshine. Additionally, the temperature will rise slowly due to northerly winds. The maximum temperature will not reach 20c in many places, so it will feel cool. It can feel cold when you get wet in the rain, so it's a good idea to have a towel ready when you go out.

The predicted maximum temperature in each region is Sapporo 21c, Sendai 15c, Tokyo 18c, Nagoya 24c, Kanazawa 19c, Osaka 24c, Kochi 26c, and Fukuoka 24c.

Weather for today, the 27th (Monday): Rain in Tohoku and eastern Japan; clear skies in western Japan with sunshine

2026/04/27 06:16

Today, the 27th (Monday), a low pressure system accompanied by a front will move eastward south of Honshu and east of Japan. It rains easily in eastern Japan and the southern part of Tohoku, and people on the Pacific side need to be careful about how it rains.



In Hokkaido, the sun will reach mainly in the morning. Clouds tend to spread in the afternoon, and there are some areas of Hokkaido with showers, especially in northern Hokkaido, so please keep an eye on changes in the sky.
Clouds will spread over the northern part of Tohoku, but there will also be periods of sunshine.

On the other hand, the southern Tohoku region and eastern Japan will experience rainy weather towards the evening. Rainfall will become stronger on the Pacific side near the low pressure system, and there is a risk of heavy rain accompanied by thunder in the morning. Be careful of strong gusts of wind such as lightning and tornadoes. Rain is expected to become heavier in the Kanto region during commuting hours. It seems best to give yourself plenty of time when going out.

Western Japan and the Nansei Islands will be clear in the morning, with sunshine reaching them. The temperature is rising and it seems like it will be easier to spend the day.
There will be some rain in the Kinki region until the morning, but the sunshine will return in the afternoon.

From today 26th (Sunday) to tomorrow 27th (Monday), rain will occur mainly on the Pacific side. Be careful of thunderstorms in western Japan.

2026/04/26 14:38

From today, the 26th (Sunday) to tomorrow, the 27th (Monday), rain is expected to fall mainly from the Pacific side of western to eastern Japan due to the influence of a front and low pressure system off the southern coast of Japan.
Today, the 26th (Sunday), 48.5 mm of heavy rain was observed in the hour until 4:56 am on Miyako Island in Miyakojima City, Okinawa Prefecture, due to the influence of the front.
Atmospheric conditions are expected to become unstable in Okinawa, Kyushu, and Kochi prefectures. Be careful of lightning, tornadoes, strong gusts of wind, and sudden heavy rain.



Currently, it is raining in some places in Okinawa Prefecture, Kyushu, Chugoku, and Shikoku regions.
After this, the low pressure system south of Kyushu is expected to move south of Shikoku into tonight. After that, the low pressure system will move eastward south of Honshu and east of Japan tomorrow, the 27th (Monday).



The area of rain is expected to gradually shift from western Japan to eastern Japan.
Today, the 26th (Sunday), it is expected to start raining in the Kinki region in the evening, in the Tokai region at night, and in some places in the Kanto region it will start raining late at night.
Tomorrow, the 27th (Monday), it will rain mainly in eastern Japan, and there will be some places in the southern part of Tohoku. Rain may peak in the Tokai and Kanto regions tomorrow during commuter and school hours. You will need a sturdy umbrella when going out.




Warm and humid air is expected to flow towards the front and low pressure system. In addition, cold air with temperatures below -15 degrees flows into the Kyushu region at an altitude of approximately 5,500 meters, making the atmospheric conditions extremely unstable.

Please be careful of thunderstorms, tornadoes, violent gusts, and sudden heavy rain in the Daitojima region of Okinawa Prefecture until late at night today, the 26th (Sunday), in northern and southern Kyushu until early evening, in the Amami region into the evening, and in Kochi Prefecture into the late evening. If there are signs that a cumulonimbus cloud is approaching, please take precautions such as moving inside a building.

In addition, winds will become stronger, especially in coastal areas. There is a possibility of heavy rain, so please be careful when going out.

In the first half of Golden Week, be careful of temperature differences; choosing clothes is key.

2026/04/26 12:24

Golden Week has begun, and many of you may have taken a day off from yesterday, the 25th (Saturday). This year's Golden Week weather tends to change periodically, so you need to be careful about how it rains. Please check the latest weather forecast frequently before heading out.



While today, the 26th (Sunday), will be as warm as early June in Sapporo, the Kanto region is expected to be as cold as normal, and tomorrow, the 27th (Monday), to be as chilly as early April.

However, on the 28th (Tuesday), temperatures are expected to change from the Kanto region to western Japan, approaching a summer day. There is a big difference in temperature from the previous day, and if you choose the wrong clothes, you may end up drenched in sweat. Furthermore, the temperature is expected to drop again in the second half of the week, making it likely to be a week with large temperature differences.





During periods of large temperature difference, it is convenient to wear thin layers and clothes that are easy to adjust. Please check the daily temperature forecast and choose clothing that is comfortable for you.

With the change of seasons, it is also a time when it is easy to get sick. Please be careful about the temperature difference and have a fun Golden Week.