Unnamed Thermal Spring

Napa County County, California · Near Napa
38.3210°N, 122.2710°W · 600 ft
83°F 600 ft Roadside Camping nearby (16.7 mi)
File:Milliken Creek Bridge, Trancas St., Napa, CA 9-5-2010 1-19-32 PM.JPG — cc by-sa 3.0

In Napa Valley, this 83-degree thermal spring emerges at 600 feet just 15 meters from Hagen Road, creating water 22 degrees warmer than ambient in the world's most prestigious wine region.

The spring flows in a landscape of vineyard-covered slopes and oak-studded hills that define modern Napa Valley. Emerging from the earth, the warm water creates a noticeable contrast to the cooler air. Rows of grapevines march across surrounding hillsides, and stone winery buildings dot the horizon. The Mediterranean climate creates dry, sunny conditions for most of the year.

History of This Spring

Napa Valley's thermal springs result from subsurface heat rising through faults in the earth's crust. The region's geology supports both viticulture and geothermal activity, with heat sources that have attracted human use for millennia. The valley's transformation into the world's finest wine region reflects its ideal climate and geology.

The spring's roadside location requires virtually no hiking effort. Year-round access is available at this convenient location. Spring through autumn provides ideal visiting weather. The proximity to wineries and restaurants makes this an easy stop during a broader Napa Valley wine tour.

Is this spring worth visiting?

Best for

  • Warm-water soaking
  • Easy day trips
  • Overnight camping trips
This spring is well suited for warm-water soaking and easy day trips.
Monthly Climate
50°
Jan
52°
Feb
54°
Mar
59°
Apr
64°
May
70°
Jun
71°
Jul
71°
Aug
70°
Sep
66°
Oct
56°
Nov
50°
Dec
Annual Precip: 23.0 in Annual Snow: 0.0 in
Best Time to Visit
January Air 50°F · Water 83°F · +33° contrast
December Air 50°F · Water 83°F · +33° contrast
February Air 52°F · Water 83°F · +31° contrast
January offers 21°F more contrast than August
Nearby Camping
Oak Shores Day Use Area (Ca) 16.7 mi away

Overview Nestled between Blue Ridge and Cedar Roughs east of Napa Valley, Lake Berryessa provides ample public recreation opportunities. Popular activities on and around the large, yet uncrowded lake include fishing, boating, water skiing, wake boarding, jet skiing, sailing, swimming, kayaking, canoeing, wildlife viewing, hiking, biking and picnicking. The Dufer Point Visitor Center offers year-round interpretive events and exhibits highlighting natural and cultural resources. Lake Berrye...

Reservable Yes
Reserve on Recreation.gov →
What to Bring
Swimsuit & towel
Water bottle Stay hydrated, especially in hot water
Camping gear Nearby camping at Oak Shores Day Use Area (Ca)
Trash bag Pack out what you pack in
References
USGS Quad: (NAPA 7.5) · NOAA: 38.0 · AMS Map: SANTA ROSA
Frequently Asked Questions
What is the water temperature at ?
has a water temperature of 83°F (28°C). This is a warm thermal spring.
Where is located?
is located in Napa County, California at 600 feet elevation, near Napa. Coordinates: 38.3210°N, 122.2710°W.
How do I get to ?
has Roadside road access, with the nearest road being Hagen Road (50 ft from the road).
Can I camp near ?
Yes, Oak Shores Day Use Area (Ca) is located nearby (16.7 miles away).
Is it safe to soak at ?
is generally safe for soaking at its recorded temperature. Access may be on private land or unconfirmed — verify current conditions before visiting. Always tell someone your plans before visiting remote hot springs.
Is crowded?
is accessible from a paved road, making it easy to reach. Weekends and holidays may be busier — consider visiting on a weekday for a quieter experience.
What should I bring to ?
Essentials for : swimsuit, towel, water bottle, camping gear, a trash bag to pack out what you pack in.
Temperature
83°F
Warm Hot Boiling
Water Temp 83°F (28°C)
Avg Air Temp 61°F
Above Ambient +22°F
Mild soaking conditions March
Access
Road Access Roadside
Nearest Road Hagen Road
Distance to Road 50 ft