JMA normals and ten years of station data for Hokkaido, Tohoku, Niigata and Nagano: typical snow depth on December 1, 15 and 31, how often December falls short, and JMA's 2026-27 winter outlook.
How much snow is on the ground in December depends on the region and on the week. The Japan Meteorological Agency (JMA) publishes daily climate normals for 1991 to 2020 and a daily record for each station, and together they show the typical snow depth on a given date and how often December falls short of it. The tables below use six JMA stations near ski areas in Hokkaido, Tohoku, Niigata and Nagano, read on December 1, 15 and 31.
All six stations are in towns or hot spring villages below the ski runs, and the upper mountain usually holds more snow than the station shows. Read the figures as a guide to timing and as a floor.
| Station (JMA) | Region | Elevation | Dec 1 | Dec 15 | Dec 31 |
|---|---|---|---|---|---|
| Sukayu | Aomori, Tohoku | 890 m | 51 cm | 107 cm | 178 cm |
| Kutchan | Hokkaido | 176 m | 22 cm | 55 cm | 88 cm |
| Nozawa Onsen | Nagano | 576 m | 4 cm | 28 cm | 68 cm |
| Yuzawa | Niigata | 340 m | 2 cm | 25 cm | 67 cm |
| Tokamachi | Niigata | 170 m | 3 cm | 27 cm | 63 cm |
| Hakuba | Nagano | 703 m | 3 cm | 12 cm | 30 cm |
The figures are JMA daily normals for the day's deepest snow (最深積雪), 1991 to 2020. Kutchan is the town that Niseko's Grand Hirafu sits in. Sukayu is a hot spring on the Hakkoda massif, close to Hakkoda. The Yuzawa station is in the town that has GALA Yuzawa, and the Hakuba station is on the valley floor.
Between December 15 and December 31 the normal depth rises by at least 60% at every station and more than doubles at the four Niigata and Nagano stations. Sukayu's normal snowfall in mid-December is about 12 cm a day, so its normal depth passes a metre by the middle of the month.
Normals smooth out the bad years. JMA's daily records for December 2016 to December 2025 show the spread:
| Station | 30 cm or more on Dec 15 | 50 cm or more on Dec 31 | Dec 31 range |
|---|---|---|---|
| Sukayu | 10 of 10 years | 10 of 10 | 143 to 340 cm |
| Kutchan | 8 of 10 | 10 of 10 | 50 to 135 cm |
| Yuzawa | 5 of 10 | 5 of 10 | 2 to 151 cm |
| Nozawa Onsen | 4 of 10 | 5 of 10 | 15 to 162 cm |
| Tokamachi | 2 of 10 | 6 of 10 | 5 to 150 cm |
| Hakuba | 0 of 9 | 1 of 10 | 0 to 58 cm |
JMA has no Hakuba reading for December 15, 2017, so that cell covers nine years.
In a normal year only the north has natural cover in the first week. Sukayu's December 1 normal is 51 cm, and the station had at least 34 cm on that date in each of the last ten years. Kutchan's normal is 22 cm, but it varies more from year to year: 51 cm on December 1, 2023, and no snow on the ground on December 1, 2025.
At the four Niigata and Nagano stations the December 1 normal is 2 to 4 cm, and in eight or nine of the last ten years the ground at the station was bare that morning. Skiing on Honshu in early December depends on high terrain and snowmaking.
By December 15 the two northern stations usually have a real base. Kutchan had 30 cm or more in eight of ten years. The exceptions were 2019 (24 cm) and 2023, when the depth fell from 51 cm on December 1 to 15 cm on December 15, so early snow in Hokkaido can still melt.
Yuzawa and Nozawa Onsen are close to a coin toss in mid-December. Yuzawa had 30 cm or more in five of ten years and was bare on December 15 in 2019, 2021 and 2023. Nozawa Onsen's station reached 30 cm in four years and was bare on that date four times. Tokamachi reached 30 cm only twice, and Hakuba's valley station never did in the nine years with data.
Honshu usually catches up in the second half of the month, often in one or two storms. In 2021 Nozawa Onsen went from no snow on December 15 to 162 cm on December 31, and Yuzawa went from 0 to 148 cm. In 2020 Yuzawa already had 103 cm by mid-month and 151 cm at year end.
Some Decembers stay thin. In 2019 and 2023 Yuzawa ended the year with 9 cm and 2 cm, and Nozawa Onsen with 25 cm and 15 cm. December 2025 was thin too: on December 31 Yuzawa had 9 cm, Nozawa Onsen 21 cm and Kutchan 50 cm, against normals of 67, 68 and 88 cm. Sukayu had 249 cm that day, above its normal of 178 cm.
Hakuba's resorts ski well above the 703 m station. Happo-one runs from 760 m to 1,831 m, so resort snow reports usually look better than the valley number. A valley normal of 30 cm on December 31 still means the lower runs and the village are often thin over New Year.
JMA's El Niño monitoring report No. 409, issued October 9, 2026, says the El Niño that began in spring 2026 reached record strength in September. The sea surface temperature in the monitoring region was 4.0°C above the reference value, beating the previous high of 3.6°C in December 1997 (records start in 1949). JMA expects the record-strength El Niño to continue into winter and puts that at 100%. The same report says Japan's weather in September did not yet show clear El Niño features. The next report is due on November 10.
JMA issued its cold season outlook for December to February on September 18, 2026. It reviewed the outlook with the three-month forecast on October 20 and left it unchanged:
| JMA forecast area | Snowfall below / near / above normal | Temperature above normal |
|---|---|---|
| Hokkaido, Sea of Japan side | 40% / 40% / 20% | 40% (Hokkaido) |
| Tohoku, Sea of Japan side | 50% / 30% / 20% | 50% (Tohoku) |
| Hokuriku (includes Niigata) | 50% / 30% / 20% | 60% |
| Kanto-Koshin (includes Nagano) | no snowfall category | 60% |
The October 20 three-month forecast also gives December on its own: a 50% chance of above-normal temperatures for Tohoku, Hokuriku and Kanto-Koshin, and 40% each for near-normal and above-normal in Hokkaido. The next three-month forecast is due on November 24.
Set against the station records, the low stations in Niigata and the Nagano valleys are the most exposed. Each of them was bare on December 15 in at least three of the last ten years. Sukayu and Kutchan did not go below 50 cm on December 31 in any of those years.
With fixed mid-December dates, Hokkaido and the Hakkoda area have the better record. On Honshu the odds improve a lot after Christmas, so flexible dates count for more than the choice of resort. In the ten days before you travel, watch the snow forecast and compare current depths on the Hokkaido, Niigata and Nagano snow reports. Opening dates by resort are on the season calendar.
Sources: JMA daily normals 1991 to 2020 and daily station data for December 2016 to 2025 (data.jma.go.jp); JMA El Niño monitoring report No. 409 (October 9, 2026); JMA cold season outlook (September 18, 2026) and three-month forecast (October 20, 2026); Happo-one course data.