One-month forecast: It's getting hotter nationwide, with "very high temperatures" from Tohoku to Okinawa, and signs of the rainy season in western and eastern Japan

2026/05/14 19:40

On the 14th (Thursday), the Japan Meteorological Agency announced the latest one-month forecast, which shows the weather outlook for the next month.



Temperatures around 1500m above the ground are expected to be higher than normal near Japan. It is expected that the whole country will be covered in warm air.
The monthly average sea level pressure forecast is that a high pressure system will extend east of Japan to the south of Japan, and in the first half of the period, the area around Okinawa and Amami will be less affected by fronts and low pressure.
On the other hand, a weak pressure trough (red dashed line in the diagram) is expected from central China to western Japan and eastern Japan, and western and eastern Japan will be susceptible to the effects of moist air circulating around fronts and the edges of high-pressure areas.



From now on, temperatures will be higher than normal across the country. On the 14th (Thursday), the Japan Meteorological Agency announced "early weather information regarding high temperatures." From around May 20th to around May 28th, regions except Hokkaido are expected to experience ``considerably high temperatures.'' Although it is not yet the start of full-fledged summer, there will be many midsummer days with maximum daytime temperatures of 30c or higher. From this weekend to next week, it is likely that there will be places in western and eastern Japan where the temperature will reach over 30 degrees Celsius. Please take all possible measures to prevent heat stroke.



Okinawa/Amami is expected to be less affected by fronts and moist air until late May due to the influence of high pressure in the south of Japan. From June onwards, there will be many cloudy and rainy days, similar to normal years.

Western and eastern Japan will be susceptible to fronts and humid air from late May onwards. There will be more cloudy and rainy days, and we will gradually move into the rainy season. Depending on the weather conditions, heavy rain may occur early in the rainy season, so please prepare early for heavy rain disasters.

[Breaking News] Localized thunderclouds are forming from Tohoku to Western Japan

2026/05/14 16:08

Today, the 14th, when temperatures rose in various places,
atmospheric conditions became extremely unstable, with localized rain clouds forming
in various places.

In Yamaguchi and Kochi prefectures, heavy rain of over 50 mm per hour has been reported,
Currently, active rain clouds have formed in Kanagawa prefecture, and lightning strikes have also been observed.





In heavy rain over a short period of time, the rain falls at once in excess of the drainage capacity, which may cause roads to flood and low-lying land to be flooded.



Please promptly move away from dangerous areas such as low-lying land, underpasses, underground spaces, etc.
Please ensure the safety of yourself and those around you by paying attention to the latest weather information.

[Rain clouds and thunderclouds are developing] Be careful of sudden thunderstorms even in urban areas! Saturdays and Sundays are sunny and it's summer heat (commentary: weather forecaster Atsuko Miyake)

2026/05/14 14:15

We need to be careful about changes in the sky today.
Even if it's sunny now, please be careful of sudden rain or thunderstorms.



Looking at the state of the rain clouds at 2:00 p.m.,
there are places with rain and thunderstorms mainly along the mountains from Tohoku to Shikoku.

Rain clouds and thunderclouds are rapidly developing from the afternoon.

There are moist air and active clouds surrounding Okinawa due to the rainy season front.

After this, there is a risk of heavy rain and thunderstorms in the Yaeyama region of Okinawa, Ishigaki Island, etc.
into tomorrow (Friday).
Please be careful of sudden heavy rain, lightning, gusts of wind, hail, etc.
There is a risk of heavy rain with a warning level.

After this, the weather will suddenly change not only along the mountains but also in the
plains near Honshu, with the possibility of thunderstorms.



Let's take a look at the rain forecast.
After this, rain clouds are likely to develop along the mountains from the Kanto region to the Tokai region,
as well as Shikoku, the Chugoku region, and the Kyushu region, by 3:00 p.m.

As strong cold air flows into the sky,
the atmospheric conditions will become extremely unstable.
Rain clouds are suddenly forming and there is a risk of heavy rain.

There is a risk of rain and thunderstorms again in urban areas (like yesterday).
And there is a risk of heavy rain and thunderstorms in Tokyo and other areas from the evening until late at night.



What should we do if a thunderstorm suddenly strikes after this
If you hear thunder, try to move to a sturdy building.
Also, when it rains in urban areas,
drainage can't keep up and the underpass may overflow.
Also, please stay away from underground facilities.
Be sure to check radar for the latest information on how long the active rain clouds will last and when the rain will stop.



Tomorrow (Friday), high pressure will cover the area around Honshu.
The unstable state of the atmosphere will be resolved tomorrow,
It looks like many places will have stable skies.

The temperature is expected to rise to 25c in Tokyo and 28c in Osaka.
We need measures against the heat.



Weekly forecast.
From now on, it will be sunny in many places through the first half of next week.
It looks like it will be quite hot on Saturday and Sunday.

The temperature in Tokyo was 28c on Saturday, which is similar to early July.
The temperature in Osaka is also expected to reach 28c on both Saturday and Sunday.
If you will be working outside for a long time, please take proper precautions against the heat.

And in Naha, it is expected to be sunny for a while.
It looks like we will be taking a break during the long rainy season.

[This year, measures against heat and bears are essential] Sendai Aoba Festival What is the weather like on Saturday and Sunday (Commentary: Weather forecaster Atsuko Miyake)

2026/05/14 13:09

The Sendai Aoba Festival will be held this Saturday and Sunday (May 16th (Sat) to May 17th (Sun), 2026).



The "Aoba Festival" colors Sendai, the capital of fresh greenery.

This year marks the 390th anniversary of the death of Date Masamune.

The main venue is Nishi Park and Jozenji Street.

The highlight is "Sendai Sparrow Dance 2026".

More than 140 festival troupes (mazura) will take part, performing splendid dance performances throughout the city over two days.



Now, let's take a look at the weather on Saturday and Sunday.

Sendai Aoba Festival, both Saturday and Sunday are expected to be sunny.
It looks like the weather will be mild and sunny due to high pressure.

It will feel a little chilly in the mornings and evenings, so you will need a jacket, but
daytime temperatures are expected to reach 24c on both Saturday and Sunday.

It seems safe to say that it is as hot as late June.

If you are going to participate in the Sparrow Dance, please take precautions against the heat.



Also, those who go to see the show need to take precautions against the heat.
Please avoid direct sunlight by wearing a hat or using a
parasol in places where there are not many people.

And be sure to drink water frequently.

This year, there have been a number of bear sightings in Sendai City.
The festival also calls for measures against bears.

Leaving trash may attract bears, so please take your trash home with you or throw it away at the trash station.

[Ocean Summary] Sea surface temperature in the western Japan Sea is 4c higher than normal

2026/05/14 12:33

A low pressure system accompanied by a front moved northeast across the Sea of Japan, and the front moved south through Kanto and Tohoku, becoming a barge in the south of Kanto and east of Kanto.
On the western continental side of the Sea of Japan, sea surface temperatures continued to be significantly higher than normal, reaching a maximum of 4 C above normal.
Below is a summary of the ocean (May 3-9, 2026)



#Pressure distribution and waves
On the 3rd, there was a low pressure system east of the Kuril Islands and the sea near the Kuril Islands, and the gradient of the atmospheric pressure increased around the front.
There were places in the east of Japan, near the Kuril Islands, and in the Sea of Okhotsk.
On the 4th, a low pressure system accompanied by a front moved northeast across the Sea of Japan.
The waves were high in the waters around Japan, and there were waves from the south of Kanto to the east of Kanto.
On the 5th, a high pressure system moved south of Japan, and a front extended from south to east of Japan.
The pressure gradient between the high pressure system and the front increased, causing waves to rise in the central Japan Sea and east of Japan.
On the 6th, a continental low pressure system moved eastward, and a high pressure system moved east of Japan.
The waves were high in the central and northern parts of the Sea of Japan, and the northern part was flooded.
From the 7th to the 8th, the waves in the seas near Japan remained calm.
On the 9th, a low pressure system accompanied by a front moved northeastward east of Japan, and waves rose again in the waters near Japan.



#Sea surface temperature
Sea surface temperatures in the Japanese waters continued to be significantly higher than normal on the western continental side, and were up to 4c higher.
In other areas, the area of sea area that was at normal level gradually expanded.
The East China Sea and the waters around the Nansei Islands continued to be at normal levels.
South of Japan, sea areas continued to be slightly higher than normal.
The sea off the coast of the Tokai region was slightly lower than normal, and from the south of Kanto to the east of Kanto was near normal.
Off the coast of Sanriku, the sea area continued to be significantly lower than normal, with temperatures up to 4 C lower.
The waters near the Kuril Islands and the Sea of Okhotsk continued to be at normal levels.

Western and eastern Japan are sunny and temperatures are rising; northern Japan is cool

2026/05/14 07:30

Yesterday, the 13th (Wednesday), it was sunny in many places from the morning, and the temperature rose mainly from western to eastern Japan, reaching 29.5 degrees Celsius in Tajimi City, Gifu Prefecture, making it just before midsummer.



Today, the 14th (Thursday), will also be covered by high pressure and will be sunny in many places. Warm air will cover eastern and western Japan, and temperatures are expected to rise during the day. In places like Nagoya, Gifu, and Okayama, the maximum temperature is expected to reach 29c, just before midsummer. Please be careful not to get heat stroke by drinking plenty of water.

On the other hand, in northern Japan, cold winds will blow from the sea, so temperatures will drop from the previous day, especially on the Pacific Ocean side and the Sea of Okhotsk side of Hokkaido. In Abashiri, the temperature is expected to be 7c, which is 12c lower than the previous day. Please take care of your physical condition as there will be a large temperature difference from the previous day.

The predicted maximum temperature in each region is Sapporo 19c, Sendai 17c, Tokyo 26c, Nagoya 29c, Kanazawa 22c, Osaka 28c, Kochi 27c, and Fukuoka 25c.

Today's weather on the 14th (Thursday): Sunny in many places, but be careful of sudden changes in the weather

2026/05/14 06:29

Today, the 14th (Thursday), the area around Japan will be covered in high pressure. It is expected to be sunny in many places, but there will still be some cold air in the upper atmosphere. Atmospheric conditions will be unstable, so pay attention to changes in the sky.



There are many places in Hokkaido that receive sunlight. The weather hasn't turned bad, and it looks like we'll be able to hang our laundry outside to dry.
There will be some showers in Tohoku by morning, but it will be sunny in many places during the day, especially on the Sea of Japan side. Inland areas, please keep an eye out for changes in the sky from the afternoon.

It is expected to be sunny in many places from eastern Japan to western Japan. However, the effects of cold air in the upper atmosphere remain, and the unstable atmosphere is expected to continue today. Rain clouds are likely to develop in inland areas and along mountains, and there is a risk of locally heavy rain. Rain clouds are moving in even on the plains, and there is a possibility of sudden heavy rain, so please be careful of sudden changes in the weather. It's safe to have a folding umbrella when going out.

Okinawa will continue to be sunny, and it looks like we will have a break during the rainy season. However, due to the approach of the front, it will start raining in the Sakishima Islands from late at night, and there is a risk of heavy rain, so it is necessary to be careful about landslides, flooding of low-lying areas, and rising river levels.

Weather and temperature summary (May 3rd to May 9th) The rainy season has begun in Okinawa and Amami, and the Kanto region is in the middle of summer for the first time this year.

2026/05/13 21:38

This is a summary of the weather and temperature from May 3 to May 9, 2026.


[About this period's weather]
#Characteristics of pressure distribution
On the 3rd, the center of the low pressure system near Chishima split into two. One moved northward through the Sea of Okhotsk, and the other, accompanied by a front, moved away to the east of the Kuril Islands. A low pressure system accompanied by a front moves east-northeast across the Yellow Sea. On the 4th, a low pressure system accompanied by a front moved from the coast of Akita toward Hokkaido. A new low-pressure system forms at the blockage point and moves northeast through the waters near Chishima, accompanied by a front. On the 5th, a developed low pressure system moved northward through the Sea of Okhotsk. A front extending from a low pressure system extended from east of Japan to near Taiwan. On the 6th, the center of the high pressure moved away to the east of Japan, and a front remained stationary from the south of Honshu to the Nansei Islands. At around 3:00 pm, Typhoon No. 5 formed near the Caroline Islands. On the 7th, a low pressure system on a stationary front running from the Sea of Japan to Hokkaido moved east-northeast from the west of the Oshima Peninsula. There is another stationary front from the south of Japan to the east of Japan, and the low pressure on the front is moving northeast off the Tokai coast. On the 8th, a low pressure system moved northeast over the Sea of Japan. Additionally, a rainy season front will extend from south of Okinawa to the East China Sea. On the 9th, a low pressure system moved east-northeast across Hokkaido. A low pressure system accompanied by another front developed and moved north toward the waters near Chishima.

#Precipitation
On the 3rd, due to the influence of a low pressure system, it rained mainly in western Japan, and the area of rain spread from north to eastern Japan. Heavy rain warning (landslide) has been announced in Ehime Prefecture. On the 4th, extremely heavy rain was observed on the Sakishima Islands in the Nansei Islands, where the front passed through in the early hours of the morning. The rainy season has been announced in Okinawa. At dawn on the 5th, there was heavy rain in the Tokai and Kinki regions, and the seasonal rain front remained stationary south of the Nansei Islands. From the evening onwards, rain clouds formed along with the front, resulting in heavy rain. On the 6th, a front stalled south of Honshu, and rain clouds developed over the Nansei Islands, where warm, humid air near the front flowed in. Heavy rain was observed in the Sakishima Islands from dawn to dawn. On the 7th, rain fell in the Izu Islands as a stationary front south of Japan moved northeast. There were also places on the Pacific side of Kyushu, Shikoku, and Honshu where clouds spread and rain fell. On the 8th, heavy rain fell mainly in northern Japan and the Sea of Japan side due to the effects of a low pressure system and front. On the 9th, it rained in Hokkaido during the day due to a low pressure system. Somewhat heavy rain was observed on the Pacific side, and the rain was the highest in May on Riku.

#Temperature
On the 3rd, the temperature rose due to the influence of warm and humid air. In Tokyo, 25.8c was observed on a summer day. On the Sea of Japan side, the temperature rose from the previous day due to the Fohn phenomenon, reaching 27.5c in Niigata. On the 4th, temperatures rose in the Kanto-Koshin region due to the Fohn phenomenon. A maximum temperature of 30.5c was observed in Nerima Ward, Tokyo. On the first midsummer day of the year in the Kanto region. Even in central Tokyo, a temperature of 28.4c was observed, the highest this year. On the 5th, sunlight reached a wide area. 26.3c on a summer day in Kiryu City, Gunma Prefecture. In Naha, the temperature was 19.2c, similar to January. On the 6th, warm air flowed into the upper atmosphere in northern Japan, and southerly winds added to the Fohn phenomenon. 27.5 degrees Celsius was recorded in Kitami, Hokkaido, and 28.4 degrees Celsius in Kamaishi, Iwate Prefecture. On the 7th, it was sunny and the temperature rose in many places other than the Pacific side of northern Hokkaido, Kyushu, Shikoku, and Honshu. It was the first midsummer day in Tohoku this year, with temperatures reaching 30.0 degrees Celsius in Ichinoseki, Iwate Prefecture. On the 8th, warm and humid air entered the low pressure system, and temperatures were higher than normal from southern Hokkaido to Okinawa. On the 9th, there were many places in eastern and western Japan where the sun was shining and the temperature was at or slightly below normal.



# Weather summary for this period (May 3rd to May 9th)
The average temperature was slightly higher or higher than normal in many places from northern Japan to eastern Japan due to the high pressure, sunlight reaching the area, and warm air flowing in from the south. In particular, temperatures in many places on the Pacific coast from Hokkaido to Kanto were above normal, and temperatures in central Tokyo were 2.4 C higher than normal.
Precipitation was significantly higher than normal in Okinawa and Amami, where the rainy season had been announced. In Naha, the rainfall was approximately 2.5 times the normal year. Hokkaido also experienced heavy rainfall due to the effects of low pressure and fronts, with Asahikawa receiving about three times more rain than normal.
Sunshine hours were at or slightly above normal, especially in Tohoku, Kanto, and the Sea of Japan side of western Japan, which were prone to being covered by high pressure. On the other hand, in Hokkaido there were many clouds and few hours of sunshine. In Okinawa and Amami, where the rainy season continues, the sunshine hours were about 70% of normal.

El Nino monitoring bulletin: El Nino phenomenon is likely to occur into the summer

2026/05/13 16:27

On the 12th (Tuesday), the Japan Meteorological Agency announced the latest El Nino monitoring bulletin.

Currently, conditions appear to be normal, with neither El Nino nor La Nina occurring, but the situation is approaching the characteristics of an El Nino. This trend is expected to gradually become more pronounced over the summer, increasing the likelihood of an El Nino phenomenon occurring.

#April Live Report
The difference in sea surface temperature in the El Nino monitoring area in April from the standard value was +0.7c, which was higher than the standard value. Additionally, the 5-month moving average used to determine the occurrence of El Nino and La Nina phenomena in February was 0.0 C, the same value as the standard value.

Convective activity remained almost at normal levels near the international date line in the equatorial Pacific Ocean. Additionally, the easterly winds (trade winds) in the lower atmosphere of the equatorial Pacific region remained strong until March, but have weakened to normal levels.

The above results indicate that although the conditions are normal, with neither El Nino nor La Nina occurring, the conditions are transitioning to the characteristics of an El Nino.



#Future outlook
According to the live report, warm water seen at the surface layer of the equatorial Pacific Ocean is moving eastward. The coupled atmosphere-ocean model predicts that this eastward movement of warm water will work to maintain sea surface temperatures in the central to eastern equatorial Pacific Ocean above normal, and that the eastward movement of warm water in the ocean surface layer, strengthened by the interaction between the atmosphere and the ocean, will continue.
As a result, the sea surface temperature in the El Nino monitoring area is predicted to rise through the fall and remain higher than the standard value.

Based on the above, we predict that there is a 90% or higher probability that an El Nino phenomenon will occur by summer.

#About the El Nino and La Nina phenomena
The El Nino phenomenon is a phenomenon in which sea surface temperatures rise above normal from the equatorial Pacific Ocean near the international date line to the coasts of South America, and this condition persists for about a year.
On the other hand, a phenomenon in which the sea surface temperature continues to be lower than normal in the same area is called a La Nina phenomenon.

When the El Nino phenomenon occurs, areas around Japan are statistically expected to experience cooler summers and warmer winters. However, the Japan Meteorological Agency predicts that there is a high possibility of high temperatures around Japan this summer, including the possibility of an El Nino phenomenon occurring.

13th (Wednesday) Temperatures are rising rapidly; thunderstorms along the mountains are expected to move south in the evening

2026/05/13 16:07

The temperature is rapidly rising during the day today, and I think there are many people who have gone beyond "sweating and cheerful" to feeling "sweating and cheerful."



As of 15:00 on the 13th,
the highest temperature of the year was observed at many locations.
Tajimi City, Gifu Prefecture 29.5c (highest this year)
Kiryu City, Gunma Prefecture 29.4c
Kita Ward, Okayama City, Okayama Prefecture 28.1c (highest this year)
Kyotanabe City, Kyoto Prefecture 28. 9c (this year's highest)
Nerima Ward, Tokyo 28.0c

On the other hand, there is strong cold air in the sky for this time of year
moving south, making the atmospheric condition extremely unstable.

It has been raining since this morning from Tohoku to Kinki and Shikoku, and many thunderstorms have been observed mainly along the mountains.
Rain clouds may move southeast into the evening and night.



Transportation may be affected depending on how it rains.
Please pay attention to the latest information.