Ski and Soak in Japan: Which Ski Areas Have a Hot Spring Source Next Door, and How Hot the Water Is

Almost every guide to skiing in Japan says there is an onsen nearby. Few say how hot the water is, or whether it is acidic enough to sting. Japan’s national geological survey has published chemical analyses of 7,203 hot spring sources across the country. We matched them to the ski areas on this site.

The numbers

251 of Japan’s 390 operating ski areas have an analysed hot spring source within 5 km. At 144 of them, at least one of those sources is 42 °C or hotter, which Japan’s standard for analysing hot springs classes as a high-temperature spring. 53 ski areas have a source within 1 km.

Top snow, with hot water close by

These are the ski areas in the top 60 for snow quality with a source of 42 °C or hotter within 2 km:

Ski area	Snow quality (of 395)	Hot source	Distance	Temperature	pH
Tengendai Kogen	9th	Ōdaira Onsen	1.8 km	52 °C	7.0
Akita Hachimantai	13th	Fukenoyu	1.0 km	96.9 °C	4.2
Shiga Kogen Kumanoyu	14th	Suzurikawa (sulphur)	0.7 km	68 °C	—
Shiga Kogen Higashidateyama	17th	Hoppo Onsen	0.7 km	82.9 °C	5.7
Kiroro	24th	a well at the resort	0.9 km	67 °C	7.4
Hakkoda Kokusai	26th	a nearby source	0.4 km	47.3 °C	6.8
Iwanai Resort	28th	a town well	1.3 km	66.5 °C	8.0
Seki Onsen	30th	Kawarayu	0.4 km	52 °C	6.7
Amihari Onsen	31st	Amihari Motoyu	1.3 km	92.5 °C	5.9
Niseko Grand Hirafu	38th	a source by the St. Moritz lift	0.8 km	65 °C	8.4
Hirayu Onsen	40th	Hirayu Onsen	0.9 km	96 °C	8.0
Manza Onsen	43rd	Manza	0.8 km	95 °C	2.0
Aizu Kogen Takatsue	45th	a hotel’s source	1.5 km	59 °C	9.0

Distances are straight lines from the ski area. ”—” means no pH was recorded.

Shiga Kogen is the standout. Six of its ski areas rank in the top 22 for snow quality and sit within 2 km of either Hoppo Onsen’s 82.9 °C source or the sulphur spring at Suzurikawa. The hottest water this close to a top-15 ski area is at Akita Hachimantai: Fukenoyu, 1 km away, at 96.9 °C. Hirayu Onsen and Manza Onsen each have water of 95 °C or more within a kilometre of the slopes, and Manza’s is strongly acidic.

Where the water is strongly acidic

Water below pH 3 counts as acidic under Japan’s standard. These ski areas have a source below pH 2.5 within 5 km:

Ski area	Source	Distance	pH	Temperature
Asahidake	a volcanic vent on the mountain	1.9 km	0.46	92.8 °C
Hakkoda Kokusai	Sukayu	3.4 km	1.0	90.7 °C
Zao Onsen	a source in Zao Onsen town	1.3 km	1.3	64.6 °C
Numajiri	Numajiri Motoyu	1.1 km	1.8	52.6 °C
Akita Hachimantai	Goshogake	0.7 km	2.0	96.5 °C
Manza Onsen	Manza	0.8 km	2.0	95 °C
Kusatsu Onsen	the Bandaikō source	1.1 km	2.0	95 °C

Asahidake’s reading is from a volcanic vent, not a bath. It is the most acidic analysis near any ski area in Japan, and a reminder that these are measurements of what comes out of the ground. Akita Hachimantai has two very different sources within a kilometre: Fukenoyu at pH 4.2 and Goshogake at pH 2.0.

Before you plan a trip around one

These are analyses of hot spring sources, not a list of baths. Some are wells, one sits beside a lift, and one is a volcanic vent. Whether you can bathe in that water, and where, is up to the onsen town and its inns.

The analyses are old. They were taken between 1910 and 2005, and a hot spring’s temperature and chemistry can change over decades. Treat them as a description of the place, not today’s reading.

Distances are straight lines. Across a mountain the road can be much longer, and some mountain roads close in winter.

Find the source near your ski area

Every Japanese ski area page on this site now lists the analysed hot spring sources within 5 km, nearest first, with temperature, pH, type and the year of analysis where one was recorded. Pages for onsen towns list the sources within 3 km of the town centre. Zao Onsen is a good one to start with.

How this was measured

Hot spring sources are processed from the hot spring analysis data in the Geothermal Information Database (GRES-DB) published by the Geological Survey of Japan, AIST: 7,203 sources, each with a location, and for most a temperature and pH. We take the centre of the small area recorded for each source and measure the straight-line distance to each ski area. The temperature and pH bands (42 °C or hotter is high-temperature, below pH 3 is acidic) follow Japan’s guidelines for analysing hot springs. Source names are translated here only where they are well known; the ski area pages show them as recorded in Japanese.

Snow quality is our score for Japan’s 395 ski areas, built from the weather when it snows (how the score works). Ski areas that have closed are left out.