Offshore and onshore wind: why surf is best early

Which way the wind blows

Wind direction in a forecast is where the wind comes from, the same as swell direction. What matters is that direction compared to the beach.

• Offshore: from the land out to sea. It blows into the face of the wave and holds it up, so it breaks clean and hollow.
• Onshore: from the sea onto the land. It pushes the top of the wave over early and puts chop on the face.
• Cross-shore: along the beach. Somewhere in between.
• Glassy: under about 4 knots, the direction stops mattering. The surface is smooth.

Why early is best

At night the land cools faster than the sea, so a light breeze often drifts from the land to the sea: offshore. In the day the land heats up, the air over it rises, and the breeze turns around and blows onshore. So on many coasts the cleanest waves are at dawn, and the afternoon is choppy. Trade winds and storms change this pattern, so read the forecast hour by hour.

Try it

Offshore at Lower Trestles is wind from the E. The shaded quarter on the dial is offshore; the grey quarter is onshore. Turn the wind and change its speed.

Where you see it on BarrelFare

Every hour of a spot forecast says offshore, cross-shore, onshore or glassy for that break, and the score drops when the wind turns onshore. The best hour of a day is often the first one.

How to read a surf report and forecast