Karuizawa 7-Day Snow Forecast

Karuizawa Long-Range Snow Forecast Updated today

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Updated 21 September 2026 02:47 PDT

Long-Range Snow Forecast for Karuizawa

Long-range (14 to 45 days) from 21 September.

For Forecast detail, see below.

Karuizawa Snow Forecast Highlights

When will there be fresh snow in Karuizawa?

Karuizawa Snow Forecast Highlights - JMA
Snowfall prediction at mid-mountain (3,437ft)
Next Snow?
There is no snow currently in the forecast for Karuizawa.

Long-range Snow Outlook for Karuizawa

Snowfall

Snow Line

Max 74°F
Min 55°F

Snow unlikely

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Karuizawa Long-Range (2 weeks+) Snow Forecast Outlook

Note :- Mountain weather is extremely dynamic; the forecast below will change. Any forecast snow may move forward or back in the forecast, and predicted snowfall depths will be revised in subsequent updates.

16 Day Weather and Snow Forecast for Karuizawa from OpenMeteo(JMA)
	Snow and Weather	Temp Town
Mon 21	Rain showers.	Max 71°F Min 66°F
Tue 22	Clear sky.	Max 74°F Min 58°F
Wed 23	Fair.	Max 66°F Min 57°F
Thu 24	Fair.	Max 74°F Min 56°F
Fri 25	Fair.	Max 71°F Min 55°F
Sat 26	Drizzle.	Max 63°F Min 57°F
Sun 27	Light rain.	Max 63°F Min 56°F

No significant snowfall is forecast for this period.

This Snow Forecast for Karuizawa, Japan gives the predicted Snowfall and Freezing Levels for the next week.

The forecast snowfall depths given are the likely average accumulations for the Lower and Upper slopes. The actual snow depth in Karuizawa, on any given trail or itinerary, may be dramatically different, particularly if the snowfall is accompanied by high winds and/or varying air temperatures.

Snow Forecasts beyond two days ahead are subject to significant change and variable reliability.

Karuizawa Snow Forecast updated at 02:47 PDT, next update expected imminently.

Ensemble forecast for Karuizawa, Japan at 3,084ft

Daily Mean Temperature (yellow line is control)

Daily Total Precipitation (blue line is control)

What are Forecast Ensembles ? Multiple forecasts from running the same weather model with slightly different inputs. The prominent line (the 'control') is the model output from standard inputs, the thinner lines are the variations. Plotted together, they show a range of possible outcomes; the closer they are, the higher the confidence.

How to read Long Range Ensemble Forecasts

These forecasts are from ECMWF EC46, a long-range, low-resolution (area) model. They may not accurately reflect local conditions and should be read as area forecasts, indicating whether the coming weeks are likely to be warmer, colder, wetter, or drier than average.

What to look for?

Temperatures trending downward at the same time as precipitation spikes upward... means snow!

Lines close together indicate a high confidence, while wider spreads signal uncertainty.

Snow Reliability

Karuizawa typically enjoys reliable snow conditions with an average snow depth of 100 cm during peak season. For the latest snow information, including current conditions and snowfall, check J2Ski for updates.

Off-Piste Safety in Karuizawa

Before skiing or snowboarding off-piste in Karuizawa, you must assess the local snow conditions. Always check the local Avalanche Risk Level and ski with appropriate safety equipment.