Dunes Beach (Half Moon Bay) Surf Report & Forecast
The open beach break north of Half Moon Bay harbour.
Current conditions
3-4 ftmax ~5 ft
Fair-Good · plunging
Modelled on real 10-foot bathymetry. These figures cover size, shape and wind. Whether the wave is makeable comes from the simulation.
- Swell
- 2.1 ft at 15s from the SW
- Wind
- 9 mph WNW cross-shore
- Tide
- 5.4 ft
- Break depth
- 5 ft
- Power
- 4 kW/m
- Water
- 61°F · 3/2 fullsuit
Updated Aug 25, 6:42 PM PDT · 2 swell trains · how this is calculated
How Dunes Beach (Half Moon Bay) is breaking right now
Solved in your browser from this spot’s seafloor and current swell
What the seafloor does to this wave
A cut straight out from Dunes Beach (Half Moon Bay), solved on the real seafloor at this hour’s swell and tide.
Why Dunes Beach (Half Moon Bay) looks like this right now
The numbers above, and what each one is actually doing to the wave.
Two swells at once
2.1 ft at 15s from the SW carrying 87% of the energy, plus 0.8 ft at 4s from the W (12%).
The long-period train is the one building your wave. It holds the most energy and reaches deepest. The shorter ones cross it, which is what makes the surface look busy and the takeoff shift around. Why period matters more than height →
The seafloor is neutral here
Kr 0.98 · 92% of modelled rays break.
Energy arrives roughly as it left deep water: this bottom neither concentrates the swell nor fans it out, so what the buoy sees is close to what you get. Why two breaks a mile apart differ →
Where it trips
5.4 ft of tide; waves are breaking in about 5 ft of water.
A wave breaks when the water gets shallow enough relative to its height, so that depth is a contour on the seafloor, and the tide slides the whole break up and down it through the day. Same swell, different spot, a few hours apart. How the tide moves the break →
Wind is cross-shore
9 mph from the WNW, against a shoreline facing 248°.
Running across the face rather than into or against it. Less destructive than a straight onshore, but it puts a texture on the wall and can make the peak harder to read.
How the sets come
About one set every 1 min, roughly 6 waves in it.
Swell arrives in groups, not evenly. That spacing is what you are really timing your paddle-out to, and it's why the lineup can look flat for minutes and then produce five waves at once. Why period matters more than height →
Dunes Beach (Half Moon Bay) surf forecast, next 6 days
Building — ~4.5 ft long-period groundswell from the WSW filling in Sat evening (+4.2 d, medium confidence)
| Day | Surf | Best window | Swell | Wind | Tide |
|---|---|---|---|---|---|
| 3-4 ft | 9am to 11amFair-Good | 2.0 ft at 14s WSW | 6 mph onshore | Low 0.0 ft 4amHigh 4.7 ft 11amLow 2.5 ft 4pmHigh 6.0 ft 10pm | |
| 3-4 ft | 10am to 1pmFair-Good | 2.1 ft at 14s WSW | 5 mph cross-shore | Low 0.1 ft 5amHigh 4.9 ft 11amLow 2.2 ft 4pmHigh 5.9 ft 10pm | |
| 3-4 ft | 10am to 1pmFair-Good | 2.1 ft at 17s WSW | 7 mph cross-shore | Low 0.2 ft 5amHigh 5.1 ft 11amLow 1.9 ft 5pmHigh 5.7 ft 11pm | |
| 3-4 ft | 8am to 5pmFair-Good | 2.4 ft at 18s WSW | 7 mph cross-shore | Low 0.5 ft 6amHigh 5.3 ft 12pmLow 1.6 ft 6pm | |
| 3-4 ft | 8am to 5pmFair | 2.8 ft at 15s WSW | 8 mph cross-shore | High 5.4 ft 12amLow 0.9 ft 6amHigh 5.5 ft 12pmLow 1.3 ft 6pm | |
| 3-4 ft | 8am to 2pmFair | 2.2 ft at 14s WSW | 10 mph onshore | High 5.0 ft 1amLow 1.4 ft 6amHigh 5.7 ft 1pmLow 1.0 ft 7pm |
Daylight hours only. The best window is the run of hours the model rates highest that day.
How Dunes Beach (Half Moon Bay) works
Wide-open sandbar peaks along the Half Moon Bay state beaches — exposed and often big, and the antidote to the crowd at Pillar Point around the corner.
- Bottom
- sand (seasonal bars)
- Best tide
- low to mid
- Best swell
- W–NW
- Suits
- intermediate
Common questions about Dunes Beach (Half Moon Bay)
- What is the best tide for Dunes Beach (Half Moon Bay)?
- Dunes Beach (Half Moon Bay) works best on low to mid tide. Tide matters because depth is what trips a wave: as the water fills in, the break slides shoreward onto a different part of the bottom, and over a shallow bank enough water stops it breaking at all. Our forecast solves each hour at that hour's real water level rather than assuming one.
- What swell direction is best for Dunes Beach (Half Moon Bay)?
- W–NW suits Dunes Beach (Half Moon Bay) best. The direction that matters is the one at the break, not the one on the buoy: the seafloor bends swell on its way in, so a spot can work on an angle the open coast is missing. We model that bending for each break rather than reporting the offshore direction.
- Is Dunes Beach (Half Moon Bay) good for beginners?
- Dunes Beach (Half Moon Bay) suits intermediate surfers, over sand. That is the wave this bottom makes on an average day, and it moves: the same break is a different proposition on a bigger swell or a different tide, so read the day's forecast rather than the label.
- What is the bottom like at Dunes Beach (Half Moon Bay)?
- sand (seasonal bars). It is the reason this break behaves the way it does: the shape of the seabed decides where the swell focuses, where it trips, and whether it spills or pitches. We model Dunes Beach (Half Moon Bay) on real 10-foot bathymetry instead of treating the seafloor as a slope.
Nearby breaks
- Pillar Point (Surfers Beach) surf report · 3-4 ft
- Mavericks surf report · ~2 ft swell
- Ross's Cove surf report · 3 ft
- Montara State Beach surf report · 2-3 ft
- Gray Whale Cove surf report · 3 ft