Fall and Winter Weather in Japan: What Global Companies Need to Know (Beyond Travel Tips)

2025.11.05

When you search for “fall and winter weather in Japan,” most results are aimed at tourists, such as fall foliage or snowy landscapes. However, behind these beautiful scenes lie a range of weather-related risks—including sudden temperature changes, dryness, heavy snowfall, and strong winds—that can significantly affect business operations.

This article outlines the key characteristics and risks of Japan’s fall and winter climate from a business perspective, and explains how to leverage weather data to effectively anticipate and respond to these risks.

Key Points of This Article

• In Japan’s fall season, large temperature shifts from summer to winter strongly influence consumer behavior. Supply and demand fluctuations are particularly significant in industries such as logistics, agriculture, and apparel. In addition, the risk of flooding from typhoons and the Akisame (fall rain) front increases.
• During winter, typical weather-related risks include heavy snowfall on the Sea of Japan side and dry, strong winds on the Pacific side. Snowfall, freezing, strong winds, and sharp temperature variations can directly affect supply chains, sales planning, and energy operations.
• Weather-related risks in fall and winter can have a direct impact on employee safety, business continuity, and profitability.
• In business operations, it is essential to utilize high-resolution, localized weather information tailored to Japan’s unique topography and climate.
• Japan Weather Association (JWA) provides industry-specific solutions designed to help companies address the country’s complex and diverse weather conditions.

For more information on the weather complexities in other seasons in Japan, please click: Why Is Japan’s Weather So Difficult to Forecast?

For the 2024 accuracy verification results of JWA Blend of Models, please click: 2024 Japan Weather Association’s Forecast Accuracy Verification Results

1. Introduction: What Are Fall and Winter Like in Japan?

1-1. Characteristics of Fall (From September through November)

• Characteristics
  • As the summer heat gradually eases, this period marks the fall rainy season and is also a time when large typhoons are likely to approach Japan. It is the season with the highest total precipitation.

• Weather Phenomena
  • In early fall, the lingering Pacific high-pressure system from summer remains strong, and late-summer heat can still be intense. In recent years, many days in September have recorded temperatures exceeding 30°C.
  • During the transition from summer to fall, the Akisame (fall rain) front forms and stagnates near Honshu. While it does not last as long as the early-summer rainy season moist air from typhoons can activate the front, sometimes causing widespread heavy rainfall.
  • Large typhoons tend to approach during this season. These fast-moving fall typhoons can bring not only heavy rain but also strong winds, high waves, and storm surges, sometimes damaging crops ready for harvest.

1-2. Characteristics of Winter (From December through February)

• Characteristics
  • Influenced by cold seasonal winds blowing from the Eurasian continent, the Sea of Japan side tends to receive frequent snowfall, making it one of the world’s heaviest snowfall regions. On the other hand, the Pacific side tends to experience dry, strong winds known as karakkaze, accompanied by prolonged periods of clear and sunny days.

• Weather Phenomena
  • When a “west-high, east-low” winter pressure pattern develops, cold seasonal winds blow out from the continent, bring snow to the Sea of Japan side. In some mountainous areas, snow accumulation can reach up to 2 meters, making them among the heaviest snowfall regions globally. During severe cold waves, heavy snow can also occur in lowland areas, sometimes causing isolated communities and causing road closures.
  • On the leeward Pacific side of the seasonal winds, dry winds prevail, resulting in frequent clear weather. However, descending winds from the mountains can sometimes become strong, causing damage from gusts.
  • When continental seasonal winds weaken, low-pressure systems tend to move along the southern coast of Honshu, bringing snow to the Pacific side as well. Cities that rarely see snow — such as Osaka, Nagoya, and Tokyo — can experience snowfall, which can have a major impact on transportation networks.

Detailed coverage of Japan’s snow will be published in January 2026.

Low-pressure systems along the southern coast

Snowfall caused by low-pressure systems along the southern coast is difficult to forecast because even minor differences in atmospheric conditions can cause large variations in outcomes. A slight shift in the low-pressure track—whether closer to the sea or further inland—can significantly change precipitation amounts. Moreover, subtle balances of temperature and humidity determine whether precipitation falls as snow or rain.

When low temperatures coincide with low humidity, heavy snowfall can occur even in lowland areas. Conversely under low temperatures but high humidity, the precipitation may instead fall as rain. In other words, the forecasting challenge lies in the precise path of the low-pressure system and the subtle differences in temperature and humidity.

2. Understanding Fall and Winter Weather Mechanisms

2-1. Fall Weather Mechanism: Why is amount of precipitation high?

• Around September and October, as summer transitions into fall, the Akisame (fall rain) front, a stationary front, appears intermittently. This front is formed when cold air from the north collides with warm, moist air from the south, and can stagnate for several days. As it gradually moves southward, it brings widespread rainfall across Japan.
  During autumn, sea surface temperatures are at their annual peak, and it is also the season for large typhoons. Even when a typhoon itself is far away, warm, humid air of tropical origin flows toward the autumn rain front, invigorating rain clouds and sometimes producing heavy rainfall over broad areas.

2-2. Winter Weather Mechanism: Why Does the Sea of Japan Get Heavy Snow While the Pacific Side Has Many Dry and Clear Days?

• Cold, dry air from the Siberian High (northwesterly seasonal wind) absorbs large amounts of water vapor as it passes over the relatively warm Sea of Japan. When this moist air ascends upon reaching the mountain ranges, snow clouds develop, causing heavy snowfall on the Sea of Japan side.
• As the air releases moisture during snowfall, it becomes dry and descends over the mountains toward the Pacific side. This results in clear, low-humidity weather on the Pacific coast, where strong, dry winds—known as karakkaze—are characteristic of the season.

3. Business Risks and Impacts During Fall and Winter in Japan

3-1. Impacts of Heavy Rainfall

• Disruptions to logistics and commuting due to flooding of railways and roads, and landslides.
• Business interruptions due to flooding of stores or facilities and power outage risks. In agriculture, crop flooding, quality deterioration, and delayed harvesting lead to economic losses.

3-2. Impacts of Temperature Drops

• Closely linked to heating demand, apparel sales, and food consumption.
• Sudden cold snaps strongly influence consumer behavior, making the accuracy of short-term forecasts directly linked to sales performance.

3-3. Impacts of Snowfall and Freezing

• Delays in logistics and transportation, factory shutdowns, and a higher risk of accidents.
• In Hokuriku, Tohoku, and Hokkaido, snowfall can exceed several tens of centimeters in a single day.
• Advance planning is required for snow removal, inventory replenishment, and energy supply and demand management. Even on the Pacific side, where heavy snow is rare, occasional heavy snowfalls can have significant business impacts in regions that are less prepared for snow.

3-4. Impacts of Dryness and Strong Winds

• Increased risk of fires, static electricity, and the spread of infectious diseases.
• In Hokuriku, Tohoku, and Hokkaido, snowfall can exceed several tens of centimeters in a single day.
• In urban areas, strong winds such as kogarashi can affect construction activities, advertising, and outdoor events.

4. Leveraging Weather Data for Business

Consumer behavior is highly influenced by daily weather conditions, which can significantly affect product and service sales.

In Japan, during the fourth quarter (October to December), data shows a general tendency for spending to decrease when temperatures are high and increase when temperatures are low. When the daily average temperature rises (or falls) by 1°C, spending in shopping centers and apparel stores decreases (or increases) by about 3%, while spending at furniture and home centers decreases (or increases) by about 2.4%.

*Japan Weather Association analyzes how daily weather conditions affect consumer spending by industry, using statistical data on credit card transactions by store type (Tokyo area, period: 2019-2023) which has been processed to prevent identification of specific individuals or merchants.

For more details, please click: “Analyzing the Social Impact of Weather Using Consumer Statistical Data – Implications for the Hot and Rainy Summer of 2024” (Only Available in Japanese)

Relying solely on past-year weather data or long-term averages may be insufficient for informed business decision-making. To succeed in the Japanese market, it is essential to leverage localized weather information tailored to Japan’s unique geography and climate characteristics.

• Examples of Available Data
  • Hourly and daily weather forecasts (temperature, snowfall, precipitation, wind speed, humidity, perceived temperature, etc.)
  • Typhoon activity and heavy rainfall
  • Weather Data API
  • GoStop (information on transportation impact risks)
  • Electric power demand forecasting
  • ENeAPI – Comprehensive API Service for the Energy Industry

• Examples of Industry-Specific Applications of Weather Information
  • Energy: Supply and demand planning for electricity and gas, and measures for peak demand.
  • Logistics: Anticipating the impact of snowfall and strong winds to optimize delivery routes.
  • Retail and apparel: Sales promotions and inventory management aligned with cold waves and the timing of first snow in the season.
  • Agriculture: Planning work schedules to avoid frost, snow damage, and low-temperature damage.
  • Construction and advertising: Assessing the risk of work stoppages due to strong winds, snowfall, and low temperatures.
  • Finance and insurance: Application to risk forecasting for natural disasters and the energy market.

• Other forecasts
  • 2-Year Long-Term Weather Forecast
    What are Long-Term Forecasts? JWA’s Proprietary “2-Year Long-Term Weather Forecast” and Its Business Applications Part 1 / Part 2
  • Product Demand Forecasting

5. Conclusion: Bringing Weather Intelligence to Your Operations

In Japan, fall and winter present a combination of risks, such as temperature fluctuations, dryness, snow, and strong winds, which can affect consumer behavior, logistics, store operations, and overall business performance. By leveraging high-resolution, localized weather forecasts, businesses can reduce costs, mitigate risks, avoid opportunity losses, ultimately leading to improved operational efficiency and stronger business outcomes.

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