Updated July 2026

Hot spring guides

Practical, data-grounded hot-spring guides: how to read water temperatures and stay safe, developed vs. primitive springs, soaking etiquette and Leave No Trace, and the best season to soak by region. Every guide is sourced. These guides are grounded in the same USGS/NOAA temperature index behind our 1,661 spring pages, plus CDC, CPSC, NPS, and Forest Service guidance — a water-temperature tier is a classification of measured data, never a clearance to soak.

Safety

Hot Spring Soaking Temperatures: What the Numbers Mean and How to Stay Safe

How hot is too hot? A plain-English guide to hot-spring water temperature, the 104°F ceiling health agencies use for hot tubs, and why a temperature tier is a measurement — not a clearance to get in.

HotSpringIndex Editorial Team · 4 min read

Planning

Developed vs. Primitive Hot Springs: What to Expect Before You Go

Commercial resort, rustic soaking box, or a wild pool at the end of a trail? The difference decides your gear, your safety margin, and whether you can legally get in at all — here is how to tell them apart.

HotSpringIndex Editorial Team · 4 min read

Etiquette

Hot Spring Etiquette and Leave No Trace: Keeping Wild Springs Wild

Undeveloped springs survive on the good behavior of the people who visit them. Here is how the seven Leave No Trace principles apply to a soak — and the small courtesies that keep a pool open for the next person.

HotSpringIndex Editorial Team · 3 min read

When to Go

Best Season for Hot Spring Soaking, by Region

The best month for a soak depends far more on where the spring is than on the water itself. A region-by-region look at the American hot-spring map — the Mountain West, the desert Southwest, the Pacific Northwest, and Alaska.

HotSpringIndex Editorial Team · 4 min read

More hot-spring guides, by email

Get new hot-spring guides and trip-planning tips by email. No spam, unsubscribe anytime.