Aetna Springs

Napa County, California · Near Angwin
38.6540°N, 122.4840°W · 814 ft
91°F 67°F air · Good soaking weather 814 ft Roadside Camping nearby (14.9 mi)

Aetna Springs is in Napa County, California, about six miles from Angwin. The water runs at soaking temperature. It is roadside, a hundred and fifty feet off Aetna Springs Road. Neither public access nor an owner is recorded, which is the first thing to sort out.

Location

Low ground, around 800 feet, and wet by western standards: two feet of rain a year and hardly any snow. Aetna Springs Road goes right by. For camping the record points to Oak Shores, a day use area some fifteen miles off. Yearly average temperature lands in the low sixties. Angwin is the only town named, and the record says nothing about the surroundings.

December through February are on file as the best months. Roadside, so no walking. With ownership and access both blank, assume nothing and ask locally before pulling off the road. No water sample is on record, nor a USGS listing, though the record does include a photo.

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 Aetna Springs.

Aerial view of the ground around Aetna Springs LiDAR bare-earth view of the same ground around Aetna 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.

Setting
Gentle slope
The ground tilts gently up to the northwest.
Highest ground nearby
150 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
145 milliwatts per square meter of heat flow

That's about twice the US average of 65. It's higher than at 92% 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
48°
Jan
50°
Feb
52°
Mar
58°
Apr
64°
May
73°
Jun
76°
Jul
76°
Aug
72°
Sep
65°
Oct
54°
Nov
47°
Dec
Annual Precip: 23.5 in Annual Snow: 0.5 in
Best Time to Visit
December Air 47°F · Water 91°F · +44° contrast
January Air 48°F · Water 91°F · +43° contrast
February Air 50°F · Water 91°F · +41° contrast
December offers 29°F more contrast than July
Current Conditions
67°F
NNW 3.6 mph 40% Good soaking weather
Tuesday 85° Low 56° Sunny
Spring is +6° warmer
Wednesday 77° Low 52° Sunny
Spring is +14° warmer
Thursday 80° Low 51° Mostly Sunny
Spring is +11° warmer
Friday 85° Low 54° Sunny
Spring is +6° warmer
Saturday 85° Low 55° Sunny
Spring is +6° warmer
Where to Stay

Some links are affiliate links. We may earn a commission at no extra cost to you.

Nearby Camping
Oak Shores Day Use Area (Ca) 14.9 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 →
Temperature
91°F
Warm Hot Boiling
Water Temp 91°F (33°C)
Avg Air Temp 61°F
Above Ambient +30°F
Warm air, warm water September
Access
Road Access Roadside
Nearest Road Aetna Springs Road
Distance to Road 151 ft
Frequently Asked Questions
What is the water temperature at Aetna Springs?
Aetna Springs has a water temperature of 91°F (33°C). This is a warm thermal spring.
Where is Aetna Springs located?
Aetna Springs is located in Napa County, California at 814 feet elevation, near Angwin. Coordinates: 38.6540°N, 122.4840°W.
How do I get to Aetna Springs?
Aetna Springs has Roadside road access, with the nearest road being Aetna Springs Road (151 ft from the road).
Can I camp near Aetna Springs?
Yes, Oak Shores Day Use Area (Ca) is located nearby (14.9 miles away).