Oshio Onsen, Ueda, Nagano Prefecture
Oshio Onsen Public Bath (Oshio Onsenkan)
A worthwhile low-cost stop for drivers who want to try a local bath fed by a cool spring that is heated for bathing. In winter, avoid an early visit: the city recommends arriving around 17:00 or later because the pool may still be warming up earlier in the day.
Check before bathing
- Opening hours
- 14:00–21:00; closed on the 15th and 30th of each month.
Spring & water temperature
- Spring-source temperature
- About 36°C, according to Ueda City's current August 2026 page.
- Bathing temperature
- Not published. In winter, the city recommends arriving around 17:00 or later because the water may not yet be comfortably warm earlier in the day.
- Spring source
- Oshio Onsen; the current facility page does not name an individual well.
- Spring classification
- Not published on the current 2026 facility page; Ueda City does note the spring's radium content.
- pH
- Not published.
- Flow rate
- Not published.
- Water handling
- Ueda City's August 2026 page says the spring water is about 36°C and is heated because of its low temperature. Circulation, disinfection and fixed bath temperature are not specified, so none are inferred.
Bathing indications
Ueda City preserves the spring's historical association with Shingen and its radium content. This is not a modern medical efficacy claim or treatment advice.
Current admission is ¥250 for adults, ¥100 for elementary and junior-high students, and free for younger children. Only an indoor bath is available. Amenities are not fully listed, so bring your own essentials.
How to read a bath profile
Spring-source temperature and actual bathing temperature are kept separate. Each score is shown independently for comparison rather than collapsed into one overall score.
