Latest One-Month Forecast: Nationwide trend of higher-than-normal temperatures; seasonal progression expected to be slow.

2026/10/08 17:01

On Thursday the 8th, the Japan Meteorological Agency released its latest one-month forecast, outlining expected weather conditions for the coming month.



Projections for average sea-level pressure over the month indicate a trough of low pressure near Northern Japan, suggesting periods where the region will be susceptible to the influence of low-pressure systems and fronts. Conversely, Eastern and Western Japan are expected to be frequently covered by high-pressure systems, particularly during the early part of the period.
Temperatures at an altitude of approximately 1,500 meters are expected to remain above average, with the entire country likely to be enveloped in warm air.

Looking ahead, Western and Eastern Japan will see many days under the influence of high-pressure systems, with sunny weather prevailing from the 10th through around the 16th?the start of the forecast period. Subsequently, the weather is expected to shift cyclically through around the 6th of the following month, with precipitation and sunshine duration likely remaining close to seasonal averages.
Northern Japan is expected to be frequently affected by low-pressure systems and fronts, particularly during the early part of the period. Consequently, precipitation levels there are projected to be higher than in Eastern and Western Japan.





Average temperatures for the month are forecast to be above normal across the country. The Japan Meteorological Agency has issued an "Early Warning Information on High Temperatures," forecasting that average temperatures nationwide will be "significantly higher" than normal for this time of year, particularly from around the 14th to the 22nd. Please take appropriate precautions, such as managing crops.
Temperatures are expected to remain above average nationwide even after this period. The progression of the seasons is slow, and the pace at which autumn foliage changes color is likely to be delayed compared to a typical year.
However, on clear, calm nights, temperatures can drop sharply by morning due to radiative cooling, leading to significant temperature differences between day and night. Please be careful to look after your health to avoid falling ill due to these sudden temperature fluctuations.

What Is a Frost Advisory? Radiational Cooling, Frost, and Crop Management

2026/10/08 14:53

Since the start of October, frost advisories have been issued with increasing frequency, particularly in northern Japan.
Temperatures are expected to drop again tomorrow morning (Friday, the 9th), and frost advisories have been issued for some areas.



So, when exactly is a "frost advisory" issued, and what should one be on the lookout for? Here is an explanation of frost advisories.

# What is a frost advisory?
A frost advisory is issued by the Japan Meteorological Agency when there is a predicted risk of damage caused by frost. Specifically, it is issued during spring and autumn when falling temperatures and resulting frost threaten to damage crops or fruit.
In short, a frost advisory serves as a warning to take precautions regarding crop management.

Frost advisories are issued during the spring and autumn seasons. They are not issued during periods like mid-winter, when crops vulnerable to frost are unlikely to be growing. While caution is required in both spring and autumn, the terms used for frost differ depending on the season:

*Hayashimo* (Early frost) Frost that occurs unusually early in the autumn season.
*Ososhimo* / *Bansho* (Late frost) Frost that occurs unusually late, from spring through early summer.

In autumn, frost can damage crops that have not yet been harvested, while in spring, it can damage crops that have sprouted and begun to grow.


# What is frost?
Frost occurs when the temperature of an object drops to 0C or below, causing water vapor in the air to undergo sublimation (transitioning directly from gas to solid) and adhere to the object as crystals.

# Weather conditions conducive to frost
Frost is likely to form on days characterized by high atmospheric pressure, clear skies (few clouds), and light winds.
On such days, radiative cooling is highly effective from night through dawn, causing a significant drop in the temperature of objects such as the ground surface and plants.
Conversely, on cloudy days, the clouds act like a lid over the ground, making it difficult for heat to escape. Additionally, because clouds radiate heat back down, the ground surface temperature does not drop as much as it does on clear days.

*Radiative cooling is the phenomenon where an object cools down by emitting heat. In this context, it refers to the process where the ground surface emits heat, cooling the air in the immediate vicinity.

The air temperatures observed and forecast by the Japan Meteorological Agency are based on measurements taken at a height of approximately 1.5 meters above the ground. However, near the ground surface, temperatures drop lower than this at night due to radiative cooling. Consequently, even if the forecast minimum temperature is 3-4C, temperatures near the ground or on plant surfaces can fall below freezing; this causes atmospheric water vapor to sublimate and form ice crystals that adhere to plants and other objects.

# Frost Damage and Countermeasures
Frost damage refers to harm caused to crops when frost settles on them. When frost forms on crops, plant cells can rupture, potentially leading to withered leaves or reduced fruit quality.

Here are some measures to take when a frost advisory is issued:

Cover crops with tunnels or protective sheeting.
This helps retain heat near the ground surface and prevents temperatures from dropping excessively.

Circulate air over the crops.
Moving the air mixes the layer near the ground with the air above, preventing the temperature near the ground from dropping too low.

Use heating equipment.
Using agricultural heaters to maintain the ambient temperature helps prevent the temperature near the ground from falling excessively.

# What else should you keep in mind?
While frost advisories are issued primarily for crop management, they also indicate that temperatures will drop significantly during the night or early morning.
You may notice the effects around your home as well-for instance, finding your car windshield completely white with frost when you head out in the morning. Additionally, since large temperature fluctuations between day and night are expected, this information can help you decide how to dress. It is worth paying attention to these advisories.

Typhoon No. 26 Moves South of Japan; Tokyo Sets Record for Longest Consecutive Days of Precipitation (Weather Summary: September 27 – October 3, 2026)

2026/10/08 14:30

Tokyo experienced rain on every single day of September this year?a first since record-keeping began in 1886. A streak of 37 consecutive days with precipitation (from August 27 to October 2) marked the longest such period on record, and the total monthly rainfall for September reached 696.5 mm, setting a new record high for the month.

The following is a summary of the weather conditions for the period from September 27 to October 3, 2026.

#Weather Summary (September 27 ? October 3)
Average temperatures were higher than normal in Okinawa/Amami and southern Kyushu, regions susceptible to warm air associated with Typhoon No. 26; temperatures were also above normal in parts of the Pacific side of Hokkaido due to the influence of a low-pressure system. In other regions, prolonged periods of rain caused by the autumn rain front and Typhoon No. 26 resulted in temperatures that were generally close to normal.

Precipitation levels tended to exceed normal values, particularly in western Japan, due to the influence of the autumn rain front and Typhoon No. 26; the Izu Islands, in the path of Typhoon No. 26, saw rainfall significantly above normal. In Hokkaido, the passage of low-pressure systems and fronts, combined with strong cold air aloft, led to above-normal precipitation in areas such as Sapporo and Asahikawa.

Sunshine duration was generally close to normal across the Pacific side of Hokkaido, the Sea of ??Japan side from Tohoku through eastern Japan, and western Japan, while Okinawa and Amami saw significantly above-normal sunshine. Conversely, the Sea of ??Japan side of Hokkaido experienced below-normal sunshine due to low-pressure systems and cold air aloft, and many areas on the Pacific side of Tohoku, as well as in Kanto and Tokai, also saw below-normal sunshine due to the influence of the autumn rain front, Typhoon No. 26, and northeasterly airflows.

[Weather Conditions During This Period]
#Characteristics of Pressure Patterns
On the 27th, a low-pressure system moved eastward from North China, passing over the Korean Peninsula; on the 28th, it intensified while accompanied by a front and moved across the Sea of ??Japan. Continuing to intensify, the low reached the Sea of ??Okhotsk on the 29th and moved away to the east of the Kuril Islands from the 30th onwards. Throughout this period, the autumn rain front remained stationary near the southern coast of Honshu from around the 27th to the 30th. Meanwhile, Typhoon No. 26 moved northeastward from waters south of Okinawa Island to waters south of Honshu; it gradually approached the autumn rain front, passed near the Izu Islands around the 1st, and transformed into an extratropical cyclone on the 2nd. On the 30th, a low-pressure system accompanied by a front intensified while moving near Primorsky Krai; it moved northeastward near Sakhalin on the 1st and reached the Sea of ??Okhotsk around the 2nd. A high-pressure system extended from the continent, creating a temporary "west-high, east-low" pressure pattern near Honshu on the 2nd, and by the 3rd, a wide area was covered by high pressure. Near the Marshall Islands, a new typhoon?Typhoon No. 27?formed around 3:00 AM on the 1st; by the 3rd, it had intensified into a large, strong typhoon and was moving near the Mariana Islands.

#Precipitation
On the 27th, rain clouds developed due to the influence of warm, moist air flowing into the vicinity of the autumn rain front from Typhoon No. 27. In Kyushu, "very heavy rain" (defined as 50mm/h or more) was observed in Omuta City, Fukuoka Prefecture, with an intensity of 71.0 mm/h. On the 28th, heavy rain continued in western Japan near the autumn rain front, while Hokkaido experienced rain due to a low-pressure system and a front moving across the Sea of ??Japan; Morino in Shiraoi Town recorded "very heavy rain" at a rate of 62.0 mm/h. On the 29th, the autumn rain front shifted slightly southward, but rain persisted across a wide area from Tohoku to Kyushu; Takefu in Echizen City, Fukui Prefecture, recorded "heavy rain" at 31.0 mm/h. On the 30th, the approach of Typhoon No. 26 brought heavy rain, particularly to the Izu Islands, with Hachijojima recording "heavy rain" at 39.0 mm/h. On the 1st, the passage of a front brought rain to eastern Hokkaido and northern Tohoku, with Imakane Town in Hokkaido recording "strong rain" at 23.5 mm/h. On the 2nd, strong cold air aloft caused snowfall in the high-altitude mountains of Hokkaido, with the season's first snowcap observed on Mount Asahi (Daisetsuzan). In Tokyo, rain fell on every single day of September?a first since record-keeping began?and the streak of consecutive days with precipitation lasted 37 days (from August 27 to October 2), marking the longest such period on record.

#Temperatures
On the 27th, temperatures rose in southern Kyushu due to warm air brought by Typhoon No. 26; Kimotsuki-Maeda in Kagoshima Prefecture recorded a "midsummer day" (high of 30C or above) at 32.8C, and temperatures remained high at the same location the following day (the 28th), climbing to 34.0C. On the 29th, temperature rises were sluggish in areas from the Chugoku region eastward where rain continued north of the autumn rain front; the high was 22.8C in Nagoya and 21.8C in Tokyo, levels typical of mid-October. On the 30th, the Kanto region was affected by a northeasterly airflow, resulting in temperatures typical of late October, such as 20.8C in Tokyo. Meanwhile, in western Japan, "midsummer day" temperatures were recorded in areas where the sun broke through. On the 1st, temperatures rose sharply in parts of the Kanto region that saw sunshine, driven by factors such as the influx of warm air associated with a typhoon. Kiryu City in Gunma Prefecture recorded a high of 33.1C, while Tokyo reached 30.0C?marking the first "midsummer day" (with a high of 30C or above) in nine days. Although many areas in Okinawa experienced midsummer-like heat on the 2nd and 3rd, the area around Honshu was covered by autumn-like air associated with a continental high-pressure system, resulting in fewer locations recording such high temperatures. In Hokkaido, cold air aloft combined with radiative cooling caused temperatures to drop; on the 3rd, Rikubetsu Town recorded a morning low of -0.1C, marking a "winter day" (with a low below 0C).

Thursday, the 8th: Calm, sunny weather across the Japanese archipelago; twin typhoons over the waters to the southeast.

2026/10/08 06:32

A high-pressure system from the continent is extending toward Japan.
While there is some cloud cover along the Sea of ??Japan coast in Hokkaido and the Tohoku region, most other areas are generally sunny.



No major weather deterioration is expected nationwide today.
It promises to be a crisp, sunny day?perfect for doing laundry.



Typhoons No. 28 and No. 29 are located far to the southeast of Japan and are moving northwest.
Typhoon No. 29 may approach the Ogasawara Islands around the 12th; please stay tuned for further updates.

Tomorrow, high pressure will continue to cover the region, bringing sunshine across the country, though the weather may deteriorate from southern Kyushu to Okinawa. During the upcoming three-day weekend, sunny skies are expected?especially in the Kanto region?making it ideal for outings, whereas Kyushu is likely to see more cloud cover.




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Forecasts for Two Typhoons: Typhoon No. 28 Heading Northeast; Typhoon No. 29 Risks Approaching the Ogasawara Islands

2026/10/07 20:03

A hurricane that moved westward from the waters near the Midway Islands has developed into Typhoon No. 28 and is currently moving west near Wake Island at a speed of 35 km/h.
Typhoon No. 29 is also moving through the waters near Wake Island at a speed of 15 km/h.



Typhoon No. 28 is expected to shift its course northward around the 9th,
and subsequently move northeastward around the 10th.
While it is not expected to have a significant impact on Japan, please stay updated with the latest information as a precaution.



Meanwhile, Typhoon No. 29 poses a risk of approaching the Ogasawara Islands around the 12th.
As there is a possibility of entering the storm's gale-force wind zone, please frequently check weather reports and the typhoon's projected path.

Weather Forecast for Tomorrow (Thursday, the 8th) and the Day After (Friday, the 9th): Autumn-like Clear Skies Nationwide; Watch Out for Temperature Fluctuations

2026/10/07 19:09

As of 3:00 PM today, Wednesday the 7th, Typhoon No. 27 has moved far away to the east of Japan and is expected to transform into an extratropical cyclone tonight. High waves caused by the typhoon persist in some areas along the Pacific coast from Northern to Eastern Japan, so caution regarding high waves is advised through tomorrow, Thursday the 8th.
Meanwhile, a strong high-pressure system is extending from the Asian continent toward the Sea of ??Japan. Consequently, today (Wednesday the 7th) has been a pleasant, sunny day across the country.



This high-pressure system is forecast to move eastward tomorrow (Thursday the 8th), covering a wide area around Japan. As a result, sunny autumn weather will continue nationwide, and many areas from Western to Eastern Japan will see high temperatures reach 25C or above?classified as a "summer day" in Japan.





Sunny weather is expected nationwide the day after tomorrow, Friday the 9th, as the region around Honshu remains under the influence of the high-pressure system. However, there may be periods of rain in Miyazaki Prefecture and the Osumi region of Kagoshima Prefecture.



Over the next two days, there will be a significant difference between morning/evening and daytime temperatures across the country, so please adjust your clothing accordingly.

Rough seas around Typhoons 26 and 27 and a low-pressure system associated with a front [Marine Summary: September 27 – October 3, 2026]

2026/10/07 15:15

After moving northward south of Okinawa, Typhoon No. 26 traveled northeastward south of Japan, causing rough to very rough seas near its center. In the latter part of the period, Typhoon No. 27 moved westward across the Mariana Islands before turning northward, causing high waves in its vicinity.
Meanwhile, low-pressure systems accompanied by fronts moved northeastward at regular intervals from the sea of Japan and Primorsky Krai, resulting in rough seas in parts of the northern sea of Japan and the sea of Okhotsk.

Regarding sea surface temperatures in waters near Japan, an area with temperatures significantly higher than normal expanded off the southeastern coast of Hokkaido, reaching a peak of 5C above average.

Summary of ocean conditions (September 27 - October 3, 2026):



# Pressure Patterns and Waves
From September 27 to October 1, Typhoon No. 26 moved northward south of Okinawa and then northeastward south of Japan.
From the 28th to the 30th, a low-pressure system moved from the sea of Japan across the sea of Okhotsk to the area east of the Kuril Islands.
Rough to very rough seas developed near the typhoon's center. High waves occurred around the low-pressure system and its associated front, resulting in rough seas in the northern sea of Japan on the 29th and in the sea of Okhotsk on the 30th.
On October 1-2, a low-pressure system moved northward from the vicinity of Primorsky Krai to Sakhalin.
On the 2nd and 3rd, a low-pressure system moved northeastward east of the Kuril Islands.
High waves occurred around the low-pressure system and front, causing rough seas in the Mamiya Strait (Tatar Strait) on the 1st and in the sea of Okhotsk on the 3rd.
From the 1st to the 3rd, Typhoon No. 27 moved westward across the Mariana Islands before turning northward. Wave heights increased around the typhoon.



# Sea Surface Temperature
In the waters around Japan, the area with temperatures slightly above normal shrank in the north but expanded in the west.
In the East China Sea, the area with temperatures slightly above normal expanded.
Temperatures around the Nansei Islands remained near normal.
Off the coasts of Shikoku and Tokai, temperatures remained near normal, just as in the previous week.
East of the Kanto region, the area with temperatures above normal persisted.
Areas with temperatures above normal began to appear off the Sanriku coast.
Off the southeastern coast of Hokkaido, the area with temperatures significantly above normal expanded, reaching a peak of 5C above normal.
In the waters near the Kuril Islands and in the sea of Okhotsk, areas with temperatures slightly above normal persisted.

Weather for Today, the 7th (Wed): Autumn sunshine across the region; pleasant weather during the day.

2026/10/07 06:08

Today, Wednesday the 7th, a migratory high-pressure system is expected to cover the area around Japan. Consequently, sunny skies will prevail across a wide area during the day.



In Northern Japan, clouds will linger along the Sea of ??Japan coast through the morning, but sunshine will gradually return. Along the Pacific coast, clear blue skies are expected to last all day. Daytime temperatures will hover around 20C in many areas, making for pleasant weather; however, please be mindful of the significant temperature difference between the day and the morning/evening hours.

In the Kanto region, skies will initially be cloudy with a chance of passing showers, but the weather is expected to improve and turn sunny as the afternoon progresses.
From the Tokai region through Western Japan, ample sunshine is expected, particularly along the Pacific coast. While humid air will cause cloudiness along the Sea of ??Japan coast, there will likely be some sunny spells. However, please keep an eye on changing weather conditions, as passing showers are possible there as well, especially in the morning. Daytime temperatures will reach around 25C in many locations, bringing dry, comfortable weather.

Sunny weather is also expected across much of Okinawa.

Typhoons 27, 28, and 29 Form Simultaneously; Coastal Areas Urged to Exercise Extreme Caution Against High Waves

2026/10/06 12:18

As of 9:00 a.m. on the 6th, large and strong Typhoon No. 27 is located near the Ogasawara Islands and is moving north at approximately 30 km/h. It has a central pressure of 950 hPa, with maximum sustained winds of 40 m/s and peak gusts of 60 m/s; gale-force winds of 25 m/s or higher extend up to 280 km east and 165 km west of the center.
The typhoon is expected to move northward near the Ogasawara Islands today (the 6th) and then proceed north-northeastward off the east coast of Japan through tomorrow (the 7th).



Due to the influence of Typhoon No. 27, caution is advised regarding high waves accompanied by swells:
- In the Ogasawara Islands, through the evening of the 6th;
- In the southern Izu Islands, from early afternoon through late at night.



High waves may crash onto the shore even if it is not raining. Please avoid approaching the coast unnecessarily.

Far to the southeast of Japan, Typhoon No. 28 is moving westward,
while Typhoon No. 29 is moving north-northwestward.



Depending on their future paths, these storms could affect the vicinity of Japan.
Please stay tuned for the latest information.

Weather for Today, Tuesday the 6th: Sunny Areas Gradually Expanding; Warm, Sweaty Weather for Western to Eastern Japan

2026/10/06 07:17

Today, Tuesday the 6th, sunny conditions will spread from the west, bringing sunshine to many areas stretching from the Kanto region westward. While rain is likely in the Hokuriku and Northern Japan regions until the morning due to the influence of a front, the weather is expected to improve during the day.





Regions from Western Japan to Kanto will be under the influence of a high-pressure system, leading to sunny skies in many areas during the day. Even in places like the Kinki region, where it is currently raining, blue skies are expected to gradually emerge.

Temperatures will rise during the day as warm air flows into the upper atmosphere. With the return of sunshine, temperatures will climb sharply; daytime highs will exceed 25 (a "summer day"), with Nagoya potentially reaching 29?just shy of a "mid-summer day" (30). Tokyo is also expected to reach 28, creating conditions where short-sleeved clothing will be comfortable. It may feel hot enough to work up a slight sweat in direct sunlight, so wearing layers that are easy to adjust is recommended.

From Hokkaido to Hokuriku, rain may persist until the morning due to the front. However, the weather will begin to improve from Hokkaido during the day, with more areas seeing sunshine.



Additionally, the Ogasawara Islands will be affected by Typhoon No. 27. Please be cautious of high waves and strong winds.