Sulphur Spring

Contra Costa County, California · Near Waldon
37.9240°N, 122.0460°W · 101 ft
75°F 61°F air · Good soaking weather 101 ft Roadside Camping nearby (22.1 mi)

A second Sulphur Spring, this one in Contra Costa County at Waldon, barely above sea level. The water came out tepid, mid seventies. It sits about a hundred feet from a road. On file, the owner line is empty and access is unconfirmed. Resolve that first.

Location

The road is unnamed on file and the spring sits beside it. Waldon is listed at zero miles, so the spring is in town or on its fringe. Snow-free, seventeen inches of rain, an annual average around sixty.

January, December and February are the months on record. The nearest camping on file is an overnight anchorage for sailing vessels twenty-two miles away, which tells you there is no real campground nearby. No fee is listed. Tepid water, no heat risk.

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 Sulphur Spring.

Aerial view of the ground around Sulphur Spring LiDAR bare-earth view of the same ground around Sulphur 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
Open ground
Flat, open ground all around.
Highest ground nearby
55 ft above the spring
Within a quarter mile, to the southwest
Cross-section through the spring

A slice through the ground from southwest to northeast, about 0.6 miles end to end.

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

Heat Below
105 milliwatts per square meter of heat flow

That's about 1½ times the US average of 65. It's higher than at 54% 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
52°
Feb
55°
Mar
59°
Apr
63°
May
68°
Jun
70°
Jul
70°
Aug
70°
Sep
65°
Oct
56°
Nov
50°
Dec
Annual Precip: 16.8 in Annual Snow: 0.1 in
Best Time to Visit
January Air 50°F · Water 75°F · +25° contrast
December Air 50°F · Water 75°F · +25° contrast
February Air 52°F · Water 75°F · +23° contrast
January offers 20°F more contrast than August
Current Conditions
61°F
Clear S 29.0 mph 77% Good soaking weather
Tuesday 84° Low 57° Sunny
Wednesday 77° Low 57° Sunny 3% precip
Thursday 84° Low 57° Sunny
Friday 87° Low 57° Sunny
Saturday 84° Low 58° Sunny 1% precip
Where to Stay

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Nearby Camping
Aquatic Park Cove, Black Point Overnight Anchoring, Sailing Vessels Only (Auxiliary Engine Ok) 22.1 mi away

Overview Aquatic Park Cove is a vibrantly urban harbor that mimics a natural anchorage and is located on the Pacific shores of one of America's great West Coast cities. San Francisco Maritime National Historical Park's Aquatic Park Cove is the small craft gateway to San Francisco. Vessels entering Aquatic Park Cove are instructed to contact the Park's permit officer on VHF marine radio channel 83A (157.175Mhz) using the call sign "Aquatic Park NPS" followed by transmission of the vessel'...

Reservable Yes
Reserve on Recreation.gov →
Temperature
75°F
Warm Hot Boiling
Water Temp 75°F (24°C)
Avg Air Temp 61°F
Above Ambient +14°F
Mild soaking conditions September
Access
Road Access Roadside
Distance to Road 110 ft
Frequently Asked Questions
What is the water temperature at Sulphur Spring?
Sulphur Spring has a water temperature of 75°F (24°C). This is a warm thermal spring.
Where is Sulphur Spring located?
Sulphur Spring is located in Contra Costa County, California at 101 feet elevation, near Waldon. Coordinates: 37.9240°N, 122.0460°W.
How do I get to Sulphur Spring?
Sulphur Spring has Roadside road access (110 ft from the road).
Can I camp near Sulphur Spring?
Yes, Aquatic Park Cove, Black Point Overnight Anchoring, Sailing Vessels Only (Auxiliary Engine Ok) is located nearby (22.1 miles away).