Warner Hot Spring

San Diego County, California · Near Julian
33.2840°N, 116.6310°W · 3,170 ft
138°F 52°F air · Good soaking weather 3,170 ft Roadside Camping nearby (4.8 mi)

Warner Hot Spring sits in San Diego County, roughly fifteen miles from Julian. The water is hot, close to the point where a soak starts to hurt, and too hot to lower yourself into at the source. The file has no entry for public access and none for land ownership. OpenStreetMap knows it by the same name, and there is a USGS site number attached.

Location

The spring is nearly on the pavement, eleven feet from the road by the record, though which road is not named in the file. Elevation runs a little over three thousand feet, so this is foothill country with real winters by Southern California standards: a few inches of snow in a typical year and a modest rain total. No land owner or unit is recorded, so you cannot assume it is public ground.

Best months per the record: December through February. Roadside, no walk. Indian Flats Campground, around five miles off, is the closest camping listed. The temperature is high enough that you should test the water before a hand goes in, and do not expect to sit in it where it surfaces. The water figures on the page go back to a December 1964 sample, so treat them as historical. Confirm ownership and access before you go.

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 Warner Hot Spring.

Aerial view of the ground around Warner Hot Spring LiDAR bare-earth view of the same ground around Warner Hot Spring
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.

Setting
Valley floor
Gentle slopes rise on both sides.
Highest ground nearby
90 ft above the spring
Within a quarter mile, to the northeast
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
93 milliwatts per square meter of heat flow

That's about 1½ times the US average of 65. It's higher than at 35% 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
50°
Jan
51°
Feb
55°
Mar
60°
Apr
64°
May
75°
Jun
80°
Jul
80°
Aug
75°
Sep
67°
Oct
57°
Nov
49°
Dec
Annual Precip: 13.8 in Annual Snow: 7.2 in
Best Time to Visit
December Air 49°F · Water 138°F · +89° contrast
January Air 50°F · Water 138°F · +88° contrast
February Air 51°F · Water 138°F · +87° contrast
December offers 31°F more contrast than August
Current Conditions
52°F
ESE 8.9 mph 84% Good soaking weather
Tuesday 84° Low 59° Sunny 1% precip
Spring is +54° warmer
Wednesday 81° Low 55° Sunny
Spring is +57° warmer
Thursday 82° Low 55° Sunny
Spring is +56° warmer
Friday 86° Low 56° Sunny
Spring is +52° warmer
Saturday 88° Low 57° Sunny
Spring is +50° warmer
Water Chemistry Sampled 1964-12-03

The water at Warner Hot Spring is slightly acidic (pH 6.6) with 355 mg/L total dissolved solids.

pH 6.6 Slightly Acidic
pH influences mineral absorption through skin
Higher mineral concentration for therapeutic soaking
Calcium 2 mg/L
May support bone density and joint health
Magnesium 0 mg/L
Known for muscle relaxation and stress relief
Sodium 95 mg/L
Supports circulation and skin hydration
Sulfate 137 mg/L
Traditionally used for skin conditions and inflammation
Chloride 25 mg/L
Natural antiseptic with skin health benefits
Where to Stay

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Nearby Camping
Indian Flats Campground 4.8 mi away

17 sites. Pacific Crest Trail Access. No Water.  The nearest water can be found at the Warner Springs Gas Station. Indian Flats will be temporarily closed for Arroyo Toad protection during breeding season beginning April 1st through at least May 31st.

Reserve on Recreation.gov →
Temperature
138°F
Warm Hot Boiling
Water Temp 138°F (59°C)
Avg Air Temp 64°F
Above Ambient +75°F
Great soaking conditions September
Access
Road Access Roadside
Distance to Road 11 ft
Frequently Asked Questions
What is the water temperature at Warner Hot Spring?
Warner Hot Spring has a water temperature of 138°F (59°C). This is considered a hot spring, well above body temperature.
Where is Warner Hot Spring located?
Warner Hot Spring is located in San Diego County, California at 3,170 feet elevation, near Julian. Coordinates: 33.2840°N, 116.6310°W.
How do I get to Warner Hot Spring?
Warner Hot Spring has Roadside road access (11 ft from the road).
Can I camp near Warner Hot Spring?
Yes, Indian Flats Campground is located nearby (4.8 miles away).
What minerals are in the water at Warner Hot Spring?
Water chemistry analysis shows the presence of pH, Total Dissolved Solids, Calcium, Magnesium, Sodium, Sulfate, Chloride. The pH is 6.6 (slightly acidic). Total dissolved solids measure 355 mg/L.
Is it safe to soak at Warner Hot Spring?
With care. At 138°F Warner Hot Spring is hot enough to need short sessions, fifteen to twenty minutes, and plenty of water. Enter slowly and get out if you feel light-headed.