Weather for the week: After unseasonable heat, there will be more cloudy and rainy days, and it looks like we will be at the beginning of the rainy season.

2026/05/18 07:25

From now on, after the early-season heat, there will be many cloudy and rainy days.



It will become sunny in many places around Honshu until the 19th (Tuesday). Temperatures are expected to be around 30 degrees Celsius in many areas, so it's important to take precautions against the heat to avoid heat stroke. The weather is likely to turn downhill in Shikoku, southern Kyushu, and Okinawa due to the effects of low pressure and fronts.

From around the 20th (Wednesday), it will be easier for fronts and low pressure systems to pass near Honshu. On the 20th (Wednesday), it will rain mainly in western Japan, and on the 21st (Thursday) it will likely spread to the Tohoku and Kanto regions. As the rain starts to fall, the temperature will drop significantly in some places from around the 21st (Thursday). The extreme heat that precedes the season seems to be calming down for now.

After that, cloudy and rainy days are expected to continue around Honshu. There will be more days when fronts and low pressure systems will pass near Honshu, and it will be the beginning of the rainy season from western to eastern Japan. Depending on the weather after that, the rainy season may be announced in some places.
It is better to prepare for heavy rain before the full-fledged rainy season begins.

The weather today, the 18th (Monday), is unseasonably hot with temperatures approaching 35 degrees Celsius or higher, so be careful of heatstroke.

2026/05/18 06:53

Today, the 18th (Monday), the area around Honshu will be widely covered by a belt-shaped high pressure system. Warm air with a temperature of over 15 degrees Celsius will flow approximately 1,500 meters above the mainland, and strong sunlight will reach the area during the day.

For this reason, temperatures will be around 30c in a wide area from Tohoku to Kyushu. Although it is not yet the start of full-fledged summer, there may be some places that record extremely hot days with temperatures of 35 degrees Celsius or higher. Toyooka City in Hyogo Prefecture is expected to experience an extremely hot day of 35 degrees Celsius, Hita City in Oita Prefecture is expected to experience an extremely hot day of 35 degrees Celsius, Kyoto and Saga are expected to experience 34 degrees Celsius, Fukushima and Nagano are expected to experience 33 degrees Celsius, and Nagoya and Osaka are expected to experience 31 degrees Celsius, making it unseasonably hot in some places.



At this time of year, your body is not yet accustomed to the heat, so the risk of heatstroke increases. Please take all possible precautions against heat stroke, such as hydrating frequently, taking breaks, and using the air conditioner without restraining yourself.

Clouds tend to spread in Hokkaido due to the influence of local fronts. In northern Hokkaido, there are likely to be some places where it will rain until late at night. If you will be returning home late, it may be a good idea to bring a folding umbrella.
In Okinawa, the atmospheric conditions are unstable due to the influence of cold air in the upper atmosphere, and there are likely to be some showers in the afternoon.

[Weekly Weather] Summer heat continues in the first half, rain gear comes in handy in the second half

2026/05/17 13:28

Over the weekend, a strong high-pressure system blanketed the area around Japan, making it unseasonably hot in many parts of the country. This high pressure system will gradually move away to the east of Japan through Tuesday. From now on, the weather is expected to be changeable as low pressure systems pass periodically.
A front will move east from the continent on Tuesday.
As a result, sluggish weather is expected mainly in western Japan from Tuesday to Wednesday. There is a possibility that another low pressure system will pass near Japan from Thursday to Saturday, and the weather is expected to deteriorate around Honshu.



Let's take a look at the latest weekly weather forecast.



Although clouds tend to spread over Hokkaido, there will be no major changes in the weather until the weekend, and the weather is expected to be relatively pleasant and sunny.

From Monday to Tuesday, the weather is clear and the sun shines brightly from eastern to western Japan, and the temperature rises rapidly. It's midsummer day in many places, with maximum temperatures around 30 degrees Celsius, so it's likely to be the start of a week in which the unseasonably hot weather will hit your body. When going out, please take strict precautions against heatstroke, such as hydrating frequently and choosing appropriate clothing.

On the other hand, in the second half of the week, the high pressure system will gradually move away to the east, and the weather will deteriorate near Honshu due to the influence of the front. As moist air tends to flow towards the front, there is a possibility that the rain may become heavier locally.
It's safe to carry a folding umbrella when you go out.
Before heading out, be sure to check the latest weather information.

Today, the 17th, is unseasonably hot in various places, 32 degrees Celsius is expected in Nagoya, and it's midsummer in Tokyo too, so be careful of heatstroke

2026/05/17 06:59

Yesterday, the 16th, the sun reached the country and the temperature rose. The highest temperature rise was in Kake, Hiroshima Prefecture, at 32.6 degrees Celsius, breaking the record for this year's highest temperature in Japan. In addition, temperatures rose mainly in inland areas, with temperatures reaching 32.3 degrees Celsius in Hita, Oita Prefecture, and 31.7 degrees Celsius in Takahashi, Okayama Prefecture, making it midsummer in 40 locations, the highest this season.



Today, the 17th, the area around Japan is expected to be covered by high pressure and sunlight will reach a wide area. Additionally, the unseasonably hot weather is likely to continue as warm air flows in at temperatures of +15 C or higher at around 1500m above the ground.

The predicted maximum temperature in each region is Sapporo 18c, Sendai 27c, Tokyo 30c, Nagoya 32c, Kanazawa 22c, Osaka 29c, Kochi 29c, and Fukuoka 28c.

From Tohoku to Western Japan, there are many places where temperatures can reach around 30c during the day, making it unseasonably hot. Temperatures are expected to rise, especially in inland areas, with temperatures expected to reach a maximum of 33 C in places such as Shobara in Hiroshima Prefecture, Kurume in Fukuoka Prefecture, and Hita in Oita Prefecture. Even in Nagoya, it is predicted to be 32 degrees Celsius, making it the hottest day of the season.
It is expected to be 30 degrees Celsius in central Tokyo, making it likely to be the first midsummer day of the season. If you are active outdoors, please take precautions against heatstroke, such as frequently drinking water and salt.

On the other hand, the temperature in Hokkaido and the Sea of Japan side of Tohoku to Hokuriku will not rise, and the temperature difference from the previous day will be large. Please be careful not to get sick due to the daily temperature difference.

Today's weather on the 17th (Sunday): Sunny skies across a wide area Okinawa is also closed during the rainy season

2026/05/17 06:25

Today, the 17th (Sunday), the area around Japan is expected to continue to be covered in high pressure. The sun is expected to reach a wide area, and temperatures are likely to rise during the day. It will be sunny even in Okinawa, which is in the rainy season.



There are times when the sun reaches Hokkaido, but the sky is cloudy. However, there are no major changes in the weather, so it should be a good day to go out.

There will be wide blue skies from Tohoku to western Japan. The weather is not bad here either, and it looks like it will be a sunny day where you can enjoy going out. Temperatures will rise during the day, with maximum temperatures reaching around 30 C in many places. Those who are active outdoors need to take precautions against heatstroke.

Okinawa will be sunny during the rainy season.

The Ogasawara Islands will be affected by the front, so it's likely to be a rainy day.

16th (Sat): Sunny and midsummer days; high temperatures continue from now on

2026/05/16 16:40

The area around Honshu was covered with high pressure, and it was sunny and there were some spots in western Japan where it was observed as a midsummer day.

[Highest temperature until 15:00 today]
Akiota Town, Yamagata District, Hiroshima Prefecture 32.6c (highest this year)
Takahashi City, Okayama Prefecture 31.7c (highest this year)
Kurume City, Fukuoka Prefecture 31.5c (this year's highest)



High temperatures are expected to continue from tomorrow onwards from eastern to western Japan.
Summer weather is expected in Joetsu for the first half of the week.



This is the time when your body is not yet used to the heat.
Let's take precautions against heat stroke so that we don't get sick due to the sudden heat.

Weekly weather: Many sunny days with high temperatures nationwide. Rain expected from the west around the 21st of next week

2026/05/15 07:20

From this weekend through next week, the area around Honshu will be covered in high pressure, so there will be many sunny days. Areas near Okinawa are not easily affected by the rainy season front, so it is likely that the holidays will continue during the rainy season.



However, temperatures nationwide will tend to be higher than normal, and it will be hot. The predicted maximum temperature is likely to be 25 degrees Celsius or higher on many days, and in some areas the daily maximum temperature is expected to continue to be close to 30 degrees Celsius. After that, it is expected that temperatures will continue to be higher than normal across the country, especially from Tohoku to Okinawa, so it will be essential to take measures such as staying hydrated frequently and taking adequate breaks to avoid heatstroke.

From around the middle of next week, around the 20th (Wednesday), clouds will gradually become more likely to spread across the country. Around the 21st (Thursday), a front and low pressure system will approach from the west, and it is likely to bring rain mainly to western Japan. Rain is expected to spread to eastern Japan around the 22nd (Friday). In some places, there will be heavy rain accompanied by thunderstorms.
There is a wide range of predictions at this point regarding the path of the low pressure system, the path of the front, and the strength and timing of rain, but please be sure to check the latest weather information that will be updated in the future.

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.