Daisetsuzan Snow Possible Oct 17; Coldest Morning Yet Oct 18

A brief burst of cold air is moving into northern Japan this weekend. Snow is possible in Hokkaido's Daisetsuzan range on Saturday, October 17, and the morning of Sunday, October 18 is forecast to be the coldest of the season so far in northern Japan. Lifts are still weeks from opening, but more news of snow on the mountains looks likely, so here is what to watch.

Saturday, Oct 17: snow possible in the Daisetsuzan range

According to tenki.jp (Japan Weather Association), air at or below 0°C is forecast to flow in at about 1,500 m over Hokkaido and northern Tohoku from Saturday the 17th into Sunday the 18th. On the 17th, snow may fall on peaks in Hokkaido's Daisetsuzan range ^[1]. The mountain weather forecast also says clouds are likely to spread over the Sea of Japan side of Hokkaido and the Daisetsuzan range on the 17th, with snow in some places ^[2].

On Sunday the 18th, the cold air aloft moves out and high pressure takes over, so both Hokkaido and Tohoku should be clear. Some wind is expected to linger in Hokkaido's mountains, though, and in the afternoon a trough approaches from the west and brings more cloud ^[2].

Sunday morning: the coldest of the season so far

The 18th should start clear, and radiative cooling will add to the chill, so northern Japan is forecast to see its coldest morning of the season. At higher elevations in Hokkaido and northern Tohoku, many places are likely to drop below 0°C (what Japan calls a fuyubi, or "winter day") ^[1]. The cold air is only a brief visitor, but Hokkaido is expected to have many more days that call for a coat ^[1].

Stronger cold air after the low passes on the 21st

STV News Hokkaido's weekly forecast says strong cold air is expected after a low-pressure system passes on Wednesday the 21st. On the morning of Thursday the 22nd, snow may fall along the mountains in Hokkaido, including around Wakkanai and Asahikawa ^[3]. The weather is forecast to turn unsettled into the new week, so anyone heading into the mountains should check the latest forecasts.

The season's first mountain snow cover so far

The first snow cover of the season in Japan was observed on the morning of October 2 on Asahidake in Hokkaido, the earliest in the country ^[4]. Starting this season, the Japan Meteorological Agency has changed how it reports summit snow cover, using analyzed snow depth instead of visual observation. Because the method differs from the earlier visual observations, dates cannot be compared directly with past years ^[5]. A tenki.jp mountain weather article dated October 15 says no mountain on Honshu has yet recorded its first snow cover ^[2].

Check the snow on the live cams

The easiest way to see whether snow has arrived on the mountains is a resort live cam. For the Daisetsuzan range, use the pages for Asahidake and Kurodake. In the Niseko area, Niseko Grand Hirafu has a view of Mt. Yotei. On the 17th, clouds are expected to come and go from Sapporo to Kutchan, with light rain likely in Otaru and Kutchan ^[3].

As of this morning, no ski resort has opened for the season, based on the site's observations. We update opening news every morning on the opening information page.

Sources

1. Coldest morning of the season forecast for Hokkaido and Tohoku on the 18th; down coats come out, possibly a record number of sub-zero locations (tenki.jp, October 16, 2026)
2. Mountain weather for the 17th and 18th: another good weekend for hiking, autumn color front moving to the Kanto-Koshin mountains (tenki.jp)
3. Hokkaido weather forecast: clear, good weekend weather, below freezing in places in the morning (STV News Hokkaido)
4. First snow cover observed on Asahidake in Hokkaido's Daisetsuzan range, earliest in Japan this season (NHK, October 2, 2026)
5. Japan Meteorological Agency: First snow cover records

Prepared with AI assistance from public sources. Always check each resort's official website for the latest information.