This is our June 24 update
La Nina Japan 2025 Winter
Our first forecast update for 2024/25 season in the Nagano resorts and Myoko Kogen
It’s the heat of summer here, but still time to crack out the crystal ball and see what the long term snow forecast could be for this 2024/25 season in Nagano and surrounding areas with La Niña Japan 2025!
Typically, during La Niña years, Japan experiences cooler and wetter conditions in winter, which can influence weather patterns and potentially affect, apart from the ski industry – agriculture, fisheries and even societal activities. However, the exact nature and intensity of these impacts can vary from year to year and area to area. At this very early stage the forecast is good with a 60% chance of a La Niña event.
Get your Nagano snow reports and weather updates for 24/25 season here!
Some Observations
On July 10, the Japan Meteorological Agency announced its “El Niño Monitoring Bulletin.” According to recent data, the current situation is normal, with neither El Niño nor La Niña occurring, but it is predicted that there is a high possibility of a La Niña occurring in the fall. The probability of heavy snowfall in the 24-25 season has increased exponentially with this forecast.
As a result of June observations, the difference between the sea surface temperature and the reference value in the El Niño monitoring area was -0.2°C, down from 0°C in May. The sea surface temperature in the equatorial Pacific Ocean was higher than normal in the west and lower than normal in the east. Therefore, it was confirmed that the overall condition is continuing to be normal. The atmosphere-ocean coupled model, a numerical model for simulating the interaction between the atmosphere and the ocean, predicts that the trade winds will become stronger in the western and central parts of the equatorial Pacific Ocean, and cold water will become even stronger in the central and eastern parts, so that the future outlook is that the temperature will remain close to or lower than the reference value through the fall. As a result, the Japan Meteorological Agency has estimated the possibility of a La Niña phenomenon occurring to be 60%.
When the La Niña phenomenon occurs, as mentioned above, the sea surface temperature in the equatorial Pacific Ocean drops, changing the atmospheric circulation pattern and increasing the probability of the Siberian high pressure system strengthening in winter. This makes it easier for cold air to flow into the vicinity of Japan, and as this cold air passes through Japan, it forms many clouds containing water vapor on the warm sea surface, and these collide with Japan’s mountainous regions, causing heavy snowfall. In addition, when the La Niña phenomenon occurs, the position and strength of the westerly winds change, making it easier for cold air to strengthen over the Japanese archipelago. This increases the possibility of increased snowfall.
Of course, heavy snowfall can sometimes be disastrous, so it’s not something to be happy about in that context. But it’s definitely good news if you’re a skier or snowboarder.
Further reading: Nagano Snow Report and Weather Conditions | Nagano Webcams
Some Observations for La Nina Japan 2024/25 (Nagano & Myoko)
At this stage we don’t have enough evidence to know what might happen specifically in Central Japan. There are many other factors that are considered when developing a winter forecast, but this year the early considerations are pointing to a promising pattern. Usually La Niña will bring above-average conditions in Myoko Kogen and Hakuba but maybe not as quite as much further inland, such as in Shiga Kogen (but still excellent!). The resorts that are the common local winners are those closer to the coast like Hiuchi Charmant, Arai, Cupid Valley and Seaside Valley.
The war on snow in Akakura Onsen.
There’s a correlation of sorts between La Nina & snowfall in some parts of Japan according to data between 1994/95 to 2015/16:
Myoko Kogen
Average 1487cm
La Nina: 1756cm
El Nino: 1308cm
Neutral: 1332cm
Yuzawa
Average 1369cm
La Nina: 1560cm
El Nino: 1121cm
Neutral: 1320cm
The worst La Nina years in this period came in around 1450cm. The best La Nina was 1876cm for Yuzawa, and 2324cm for Myoko Kogen. Both these ski resort areas lie either side of northern Nagano.
Japanese media are reporting that La Nina can cause abnormally heavy snow. Whilst not guaranteed there is a reasonable correlation. The emergence of La Niña Japan was also observed from December 2005 to February 2006, when around 150 people died as a result of heavy snow across Japan. Snows were also heavy in another recent occurrence of La Niña in 2011/12.
A great 2024/25 Nagano winter coming up we hope!
The Japan Meteorological Agency’s expectation that the La Niña Japan winter 2024/25 may appear aligns with the U.S. National Oceanic and Atmospheric Administration which upgraded it’s forecast to a 79% chance of the phenomenon appearing during the upcoming Northern Hemisphere winter.
We’ll be updating this page as further forecasts are released between August and November 2024
Book now to get the best La Niña Japan deals!
Can’t find what you want? Send us a accommodation request or ask a question.
Note to other website owners. Whilst we know you and your guests/clients/visitors will be excited to read about La Niña Japan in 2024/25, if you choose to reference some or all of the above you must ensure that you include the acknowledgment to us. Thank you!