Warm Springs

Boise County, Idaho · Near Idaho City
43.8160°N, 115.8630°W · 3,850 ft
108°F 33°F air · Good soaking weather 3,850 ft Roadside Camping nearby (0.6 mi)
Aerial view of the ground around Warm Springs LiDAR bare-earth view of the same ground around Warm Springs
Aerial LiDAR bare earth

Drag the handle to compare the two views. The orange dot marks the spring, in a frame about three quarters of a mile wide.

Warm Springs is a plain name for a spring on the outskirts of Idaho City in Boise County, under two miles from town. The 1981 reading lands at the upper end of soaking warm, hotter than most bathwater, and right at the edge where some people find it too much. Who owns the ground is not recorded, and no access status appears either, so despite being nearly in town it is unconfirmed as a place you can visit.

Location

The record puts the nearest road four feet from the spring, so it is at the roadside, whatever the road is; no name is given. The altitude is modest, under four thousand feet. Winter snow comes in at around ninety inches a year. Moisture overall is middling.

Timing on record favors the middle of winter. Grayback campground is barely half a mile away. At the recorded temperature the water will feel hot going in and will not scald. Confirm you may enter the site, since ownership and access are both blanks in the record. The sample is from May 1981.

Terrain

Aircraft with laser scanners measured this ground to within inches. The scan strips out trees and buildings, leaving the bare shape of the land around Warm Springs.

Setting
Hillside
The spring sits on a steep slope that climbs to the northwest.
Highest ground nearby
310 ft above the spring
Within a quarter mile, to the northwest
Cross-section through the spring

A slice through the ground from northwest to southeast, about 0.6 miles end to end.

Elevation data: USGS 3D Elevation Program. Aerial imagery: USGS The National Map. Public domain.

Heat Below
131 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 81% of the springs on this site.

Heat flow measures the warmth working its way up through the ground from deep inside the earth. Where it runs high, rain and snowmelt that seep down through cracks in the rock come back up hot.

Heat flow estimate: Stanford Thermal Earth Model (Aljubran & Horne, 2024), CC BY 4.0.

Monthly Climate
27°
Jan
31°
Feb
37°
Mar
43°
Apr
53°
May
63°
Jun
73°
Jul
72°
Aug
62°
Sep
48°
Oct
35°
Nov
26°
Dec
Annual Precip: 26.9 in Annual Snow: 87.4 in
Best Time to Visit
December Air 26°F · Water 108°F · +82° contrast
January Air 27°F · Water 108°F · +81° contrast
February Air 31°F · Water 108°F · +78° contrast
December offers 47°F more contrast than July
Current Conditions
33°F
NW 0.0 mph 98% Good soaking weather
Today 76° Low 38° Sunny
Spring is +32° warmer
Wednesday 83° Low 43° Sunny
Spring is +25° warmer
Thursday 75° Low 40° Rain Showers Likely 69% precip
Spring is +33° warmer
Friday 76° Low 38° Areas Of Fog then Slight Chance Rain Showers 16% precip
Spring is +32° warmer
Saturday 80° Low 40° Patchy Fog then Sunny 2% precip
Spring is +28° warmer
Water Chemistry Sampled 1981-05-11

The water at Warm Springs is alkaline (pH 9.5).

pH 9.5 Alkaline
pH influences mineral absorption through skin
Calcium 2 mg/L
May support bone density and joint health
Magnesium 0 mg/L
Known for muscle relaxation and stress relief
Sodium 65 mg/L
Supports circulation and skin hydration
Sulfate 22 mg/L
Traditionally used for skin conditions and inflammation
Chloride 3 mg/L
Natural antiseptic with skin health benefits
Where to Stay

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Nearby Camping
Grayback 0.6 mi away

Overview Grayback Campground is located 36 miles northeast of Boise, Idaho, just off scenic Highway 21. Historic Idaho City is just two miles north of the campground. Visitors enjoy fishing in Mores Creek and exploring the Grayback Gulch Trail.   Recreation Mores Creek can be accessed just below the campground. Anglers fish for whitefish and rainbow trout. Grayback Loop Trail begins within the site, offering a 1-mile footpath for hikers. Numerous trail opportunities are in the area just nort...

Reservable Yes
Reserve on Recreation.gov →
Temperature
108°F
Warm Hot Boiling
Water Temp 108°F (42°C)
Avg Air Temp 48°F
Above Ambient +61°F
Good soaking conditions September
Access
Road Access Roadside
Distance to Road 4 ft
Frequently Asked Questions
What is the water temperature at Warm Springs?
Warm Springs has a water temperature of 108°F (42°C). This is considered a hot spring, well above body temperature.
Where is Warm Springs located?
Warm Springs is located in Boise County, Idaho at 3,850 feet elevation, near Idaho City. Coordinates: 43.8160°N, 115.8630°W.
How do I get to Warm Springs?
Warm Springs has Roadside road access (4 ft from the road).
Can I camp near Warm Springs?
Yes, Grayback is located nearby (0.6 miles away).
What minerals are in the water at Warm Springs?
Water chemistry analysis shows the presence of pH, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 9.5 (alkaline).
Sources: USGS NWIS, Wikipedia