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Winter 2025 Arrives Early: Be Alert for Severe Cold and Heavy Snow from December – What Are the Impacts on Business?【Weather Marketing Report】
2025.10.29
Key Points for Japan’s Winter 2025/26
Japan’s winter in 2025 is expected to resemble conditions typical of a La Niña event in the first half of the season.
From December, midwinter-level cold air is predicted to move southward earlier than usual, causing a sharp drop in temperatures. Caution will be needed for localized heavy snow, especially on the Sea of Japan side. In the latter half of the winter, La Niña characteristics are expected to weaken, and in February 2026, spring-like conditions may arrive earlier than usual.
What Are the Weather Trends for Japan’s Winter 2025/26 (December–February)?
Seasonal characteristics such as warm winters or cool summers are typically influenced by variations in sea surface temperatures across the tropical Pacific Ocean—notably the El Niño*1 and the La Niña*2 phenomena.
At present, neither El Niño nor La Niña conditions are occurring, meaning the Pacific situation is considered neutral. However, toward the beginning of winter, conditions are expected to shift to a La Niña-like pattern.
When La Niña develops, the winter pressure pattern over Japan tends to strengthen in a west-high/east-low configuration, and low-pressure systems are more likely to intensify near northern Japan. As a result, stormy weather tends to occur across northern regions, while cold air masses sweep in from the west, making western Japan often colder than average in particular.
During the previous 2024/25 winter season, sea surface temperatures and pressure patterns resembled those during La Niña. As a result, strong cold air masses dominated, especially in December and February, leading to severe cold nationwide, with and temperatures in western Japan and the Okinawa–Amami regions recording below-average temperatures.
In the upcoming 2025/26 winter, La Niña-like characteristics are also expected to appear in the first half of the season. Following a warm October, temperatures are expected to drop sharply in November, indicating the approach of winter. As early as December, midwinter-level cold air is forecast to move southward. Because sea surface temperatures in the Sea of Japan are higher than usual, snow clouds will easily develop, increasing the risk of localized heavy snowfall, mainly on the Sea of Japan side.
In contrast, La Niña characteristics are expected to weaken during the latter half of winter. While February 2025 brought severe cold across the Japan archipelago, February 2026 may see an earlier arrival of spring-like conditions.
According to the Cold-Season Outlook released by Japan Meteorological Agency’s (issued September 22, 2025, for December 2025–February 2026), winter temperatures are expected to be around normal.
— For the relationship between temperature and product demand, please refer to Relationship between sales of autumn–winter foods and temperatures when people start to feel cool (Only Available in Japanese)
Extreme weekly fluctuations—such as unusually high or low temperatures or prolonged rainfall—can often be predicted up to one month in advance. It is important to monitor the latest weather updates and adjust business plans accordingly.
*1 El Niño phenomenon: A climate event in which sea surface temperatures from near the International Date Line in the central equatorial Pacific to the coast of South America become higher than normal, and the condition persists for about one year. In Japan, El Niño tends to bring cooler summers and warmer winters.
*2 La Niña phenomenon: A climate event in which sea surface temperatures from near the International Date Line in the central equatorial Pacific to the coast of South America become lower than normal, and the condition continues for about one year. In Japan, La Niña tends to bring hotter summers and colder winters.
Note: This forecast is based on variations in tropical ocean conditions such as El Niño and La Niña phenomenon. When no clear signals observed in tropical ocean patterns, forecasting becomes more difficult and accuracy may decrease. In addition, pronounced warm or cold temperatures lasting several weeks or prolonged rainfall can only be predicted less than one month in advance. Please take these limitations into account when using this information.
Impacts of Japan’s 2025–2026 Winter Weather on Business
Manufacturing
From November to December, the sudden onset of cold weather may cause a sudden increase in demand for winter-related products such as hot pot ingredients, hot beverages, and disposable body warmers.
Particular attention is required in the first half of winter for potential disruptions to logistics due to heavy localized snowfall.
- Product Demand Forecast Consulting
- Weather x Market Forecast (Only Available in Japanese)
Retail
From November to December, there is likely to be a sudden shift from fall products to winter products.
As weather and temperature forecasts become more accurate about two weeks in advance, please stay alert to the latest weather information.
Apparel
Full-scale demand for coats and thick sweaters may be delayed, but the number of days with midwinter-level cold is likely to increase in December.
As some spring-like days may appear in the latter half of the season, please take care with winter inventory management.
Logistics
In December especially, the risk of localized heavy snowfall is likely to increase due to sudden drops in temperature, mainly along the Sea of Japan side.
Since the snow forecasts become more accurate about one week in advance, it is recommended to review vehicle allocation and personnel plans frequently based on the latest forecasts.
Energy
From December onward, the cold weather is expected to intensify, and demand for electricity and gas may rise early in the season. It may be necessary to secure sufficient supply capacity for peak hours and to encourage power and gas conservation.
In areas along the Sea of Japan and in northern Japan, heavy snow and blizzards may delay the delivery of fuel and materials. It is recommended to review supply–demand and fuel plans as needed, based on the latest forecasts from one to two weeks in advance.
- ENeAPI – API Service for Energy Providers
- 2-Year Long-Term Weather Forecast (Only Available in Japanese)
This Summer’s Weather Forecasts and Results
In its Weather Marketing Report: 2025 Weather Outlook – A Colder Winter Followed by Early Spring, and a Hot Summer with Sharp Contrasts (Only Available in Japanese) issued on December 20, 2024, Japan Weather Association predicted “an early end to the rainy season”, “extremely hot summer temperatures”, and “a lingering late-summer heat.”
In fact, the 2025 summer season saw a record-early end to the rainy season and the hottest summer on record, followed by a prolonged period of severe lingering late-summer heat. As of December 2024, Japan Weather Association was able to forecast the general summer trend.
Reducing Business Losses by Utilizing Long-Term Weather Forecasts
Weather is one of the few areas where future conditions can be predicted using physical models. This predictive ability is highly valuable for businesses, as weather impacts many industries. It’s estimated that one-third of all global industries face weather-related risks*3, highlighting the strong link between weather and business.
By planning production based on weather forecasts rather than solely on the previous year’s performance, it can be possible to reduce weather-related disposal losses and opportunity losses by around 30% to 40%.
Japan Weather Association provides a wide range of weather data—from short-term forecasts covering the next few hours to long-term outlooks extending up to two years ahead—and offers consulting services based on expert meteorological knowledge.
2-Year Long-Term Weather Forecast (Only Available in Japanese)
JWA has developed the industry’s first forecasting method that offers higher accuracy and longer forecast periods than conventional approaches. This service provides numerical forecasts, including monthly temperature,recipitation/snowfall, and sunshine duration.
In addition to data provision, we also offer consulting services to help clients make effective use of long-term forecasts.
In the 2-Year Long-Term Weather Forecast (Only Available in Japanese), we provide not only seasonal and monthly weather trends but also two-year-ahead demand forecasts for specific products, along with proposals for inventory and sales promotion timing. We also offer forecasts and consulting on weather trends from the summer of 2026 through 2027.
For details on 2-Year Long-Term Weather Forecasts, please click： What are Long-Term Forecasts? JWA’s Proprietary “2-Year Long-Term Weather Forecast” and Its Business Applications Part 1 / Part 2
For information on the accuracy and use cases of the 2-Year Long-Term Weather Forecast, please click:“ Accuracy and Use Cases of the Two-Year Long-Term Weather Forecast – Capturing the Remarkable Extreme Heat of Summer 2025 in Advance and Contributing to Preparedness for ‘Weather Risks in Business’” (Only Available in Japanese)
Please feel free to please visit: Contact Us for details.
Other JWA Services
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JWA’s weather API is designed to allow developers to access highly accurate weather information for any location. Data such as temperature, humidity, precipitation, snowfall, wind direction and speed, and general weather conditions can be retrieved in a single request through a user-friendly API.
For the overview, please see: Weather API Overview -
Analyze product sales and weather data to forecast product demand and customer traffic to adjust production volume and optimize inventory management.
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Logistics-oriented GoStop Management System
Provides transport impact risk information caused by weather conditions, supporting decisions that help protect lives and cargo in logistics operations.
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*3 Dutton, J. A., Bull. Amer. Meteor. Soc., 83, 1303-1311 (2002)