Greenpia Onuma is a ski area in Hokkaido, Japan, on slopes between roughly 180 and 338 m. Its mapped area is about 1.6 km across, with 7 marked runs and 2 lifts (about 4.1 km of piste in all).
Over the last twelve winters the ERA5 weather model gives it 169 cm of snowfall a season, 297th of the 397 ski areas we measure in Japan. It swings a lot from year to year: the biggest winter, 2017/18 (246 cm), brought more than twice as much as the leanest, 2015/16 (113 cm). January is usually the snowiest month, with about 50 cm. Weather models read low in the mountains: a Japan Meteorological Agency station 6.5 km away measured 381 cm a winter over the last three seasons, against 187 cm from the model. Snowfall days average −2.9 °C at mid-mountain, and its snow-quality score ranks 244th of 397 in Japan.
Below are links to 2 official live cameras.
Snow depth and the seven-day outlook appear here once snow starts to fall. Until then, the long-run record comes first.
Elevation range is estimated by sampling points across the ski area.
How much snow it gets
Measured by us across 3,069 ski areas by one identical method. These are not the resort’s own published figures.
The tick marks the median across every Japanese ski area we measure. All four bars run the same way — longer is better.
The quality score deliberately excludes how much snow falls — it uses temperature, frequency, rain and wind. Snowing a lot and snowing well are different things.
Compared with what is nearby
Within 50 km straight line. Measured the same way, so the ranks compare directly. Ski areas a few kilometres apart share a weather grid cell and can return the same figure.
| Ski area | Distance | Seasonal snowfall | World rank |
|---|---|---|---|
| Niyama Kogen Ski Area | 8.4 km | 155 cm | 1601 |
| Hakodate Nanae Snowpark | 14 km | 153 cm | 1621 |
| Yakumo Choei Ski Area | 38 km | 179 cm | 1330 |
| Furusatonomori Ski Area | 39 km | 159 cm | 1553 |
| Kaminokuni Chomin Ski Area | 41 km | 240 cm | 800 |
When it falls, and how winters differ
Month by month
Month by month, the most snow falls in January. March brings 78% of January’s snowfall. That is a gentler fall than the median for ski areas in Japan (52%). For skiing, though, the amount matters more than the share: March brings 39 cm, less than the median of 46 cm.
Winter by winter
Across the 12 winters measured, the average is 169 cm, and 6 of them fell short of it. The leanest was 2015/16 with 113 cm; the biggest was 2017/18 with 246 cm (2.2 times as much). For 63% of the 397 ski areas in Japan, the leanest winter was the same 2015/16: bad winters tend to hit a whole region at once.
Snowfall each winter (December–March total). The dashed line is the average; the numbers mark the leanest and the biggest winter.
Runs and lifts
Counted from the runs and lifts drawn on OpenStreetMap, within the boundary of the ski area. These are not the resort’s own published figures.
Run map
The shape of the mountain
Which way the slopes face
56% of the vertical on the runs descends to the north or east. Those slopes get the least sun, so the snow lasts longer.
By difficulty
Lift types
- Chairlift2
See past trail maps on Skimap.org ↗
Source: OpenSkiMap (© OpenStreetMap contributors, ODbL 1.0). How finely ski areas are drawn varies by region, so treat the counts as indicative. Vertical is the difference between the highest and lowest points of the mapped runs and lifts.
Live Cameras
Road conditions decide whether you can get there at all. Check before you leave.
Footage remains the copyright of each operator. JAPANSNOWLINE neither stores nor redistributes it.
Hakodate and Onuma webcams & snow report — all 3 ski areas →
What was actually measured nearby
Total snowfall from December to March recorded at the 森 weather station — 6.5 km from this ski area, 134 m below its mid-slope.
| Three-season average | 381 cm |
| 2023/24 | 380 cm |
| 2024/25 | 468 cm |
| 2025/26 | 295 cm |
The figure calculated on this page is 187 cm.
A weather station is not a ski slope. We picked one at a similar elevation, but it stands in a valley or a village. More snow falls on the mountain above it. We have not tried to guess how much more.
Source: Japan Meteorological Agency historical records
Hot springs nearby, as analysed
6 hot spring sources with published analyses lie within 5 km of this ski area, nearest first (the hottest is 49.3 °C).
| Source | Distance | Temperature | pH | Type | Analysed |
|---|---|---|---|---|---|
| 森赤井川グリンピア大沼井 | 0.9 km | 35.3℃ warm | 8.3 mildly alkaline | — | — |
| 駒ヶ岳寿観光駒ヶ岳R1 | 2.5 km | 42℃ hot | 8.1 mildly alkaline | — | — |
| 駒ヶ岳ワールド牧場2号井 | 3.2 km | 40.8℃ warm | 8.7 alkaline | alkaline simple | — |
| 西大沼西武ゴルフ場R-3 | 4.5 km | 42.2℃ hot | 8 mildly alkaline | simple | — |
| 西大沼じゅんさい沼温泉R1号 | 4.5 km | 31℃ lukewarm | 7.5 mildly alkaline | — | — |
| 森赤井川日本石油東大沼荘 | 4.7 km | 49.3℃ hot | 7.8 mildly alkaline | simple | — |
These are analyses of hot spring sources, not a list of baths you can visit. They date from 1910 to 2005, many from decades ago, so today’s temperature and chemistry may differ. Names are as recorded in Japanese. Temperature and pH bands follow Japan’s standard for analysing hot springs.
Source: processed from the hot spring analysis data in the Geothermal Information Database (GRES-DB), Geological Survey of Japan, AIST
Worth seeing nearby
Places within 20 km of this ski area, for a day off the slopes or an evening. Chosen from those most read about on Wikipedia, favouring places with an English Wikipedia article, and listed nearest first.
| Place | Type | Distance |
|---|---|---|
| Ōnuma Quasi-National Park大沼国定公園 | Nature | 6 km |
| Ōnuma大沼 (七飯町) | Nature | 7.2 km |
| Hokkaidō Koma-ga-take北海道駒ヶ岳 | Mountain | 9 km |
| オニウシ公園 | Park | 10.6 km |
| 濁川温泉 | Hot spring town | 17.6 km |
| Roadside station Shikabe Kanketsusen park道の駅しかべ間歇泉公園 | Park | 19.4 km |
Based on the Japanese Wikipedia lists of sights in each prefecture, as compiled in travel-log-data (CC BY-SA 4.0). English names from Wikidata (CC0). The content of this section is available under CC BY-SA 4.0.
Map
Where it sits relative to nearby resorts. For a piste map, see the official site.
Official piste map ↗Places to stay nearby
2 properties on Rakuten Travel lie within 3 km of this ski area, listed cheapest first.
| Property | From | Rating | Distance | Getting there |
|---|---|---|---|---|
| リブマックスリゾート函館 グリーンピア大沼 | ¥3,000 | 4.55 688 reviews | 0.9 km | 道央道 大沼公園ＩＣより約２分・大沼公園駅より車で１０分（予約制無料送迎バス有） |
| ペンション 森の中の小さな家 | ¥5,000 | 4.60 105 reviews | 2.3 km | ＪＲ大沼公園駅からお車で７分／函館市内からお車で５０分 |
Contains advertising · Property data by Rakuten Travel (Supported by Rakuten Developers)
Stay nearby
6 places within 12 km of the slopes. Most of them do not take online bookings — open the map for contact details.
Accommodation data: OpenStreetMap
More places to look
Guides covering Hokkaido
- A Historic El Niño Is Forecast. Here Is What the Last Big One Did to Japan's Snow. NOAA gives a very strong El Niño better than a 90% chance this winter. We measured every Japanese ski area across the last 12 winters: El Niño winters ran 88% of normal, and the strongest of the twelve left Japan at 63%. But Hakuba held 92% of its average that winter while Niseko fell to 57%.
- Which Famous Ski Resorts Actually Get the Most Snow? 24 Names, Measured Niseko is 526th in the world for snowfall. Zermatt is 554th, Jackson Hole 924th, Aspen 1,201st. Measured identically across 3,069 ski areas, the names everyone books and the places it actually snows turn out to be two different lists.
- Australia Just Had Its Worst Season in Twenty Years. Here Is What Japan's 12-Winter Record Says About Booking It Instead. Snow depth at Spencers Creek peaked at 94.5 cm, the third lowest since 1954, and resorts closed in August. Our own measure — snowfall, not depth — puts Australia at 50% of its 12-year average. The gap between those two numbers is the story: it was the warmth, not only the lack of snow. New Zealand, meanwhile, finished at 108% of normal.
Updated: 8 Oct 2026, 00:52