How do I read a surf forecast?
A surf forecast is five numbers: wave height, swell period, swell direction, wind, and tide. Read them in that order. Height tells you whether there is anything to surf, period tells you whether it will have any power, and wind decides whether it will be clean or a mess.
The five numbers, and what each one actually tells you
| Number | What it tells you | Rough guide |
|---|---|---|
| Wave height | How big the face of the wave is | 1–2 ft beginner · 3–5 ft intermediate · 6 ft+ experienced |
| Swell period | How much power the wave carries | Under 8s weak · 10–14s good · 15s+ powerful |
| Swell direction | Whether the swell can reach the spot at all | Compare it to the direction the beach faces |
| Wind speed and direction | Whether the surface is clean or chopped up | Offshore is clean · onshore over 15 kt is messy |
| Tide | Whether the spot works right now | Some breaks only work on one part of the tide |
Which number matters most?
Wind, then period, then height. Most people read height first because it is the biggest number on the screen, and it is the one that misleads them most often.
A 3 ft forecast with a 14 second period and light offshore wind is a good session. The same 3 ft with a 6 second period and 20 knots of onshore wind is unsurfable chop. Same height, completely different day.
Why do two spots with the same forecast look different?
Because a forecast describes the ocean offshore, not the beach. What reaches the sand depends on which way the coast faces, what the seabed does to the swell, and whether headlands or breakwaters block the wind.
A swell arriving from the west lights up a west-facing beach and barely registers two headlands north, where the same swell arrives at an angle and loses most of its size. This is the single biggest reason a forecast feels wrong: it was right about the ocean and you were standing somewhere it could not reach.
What does a star rating actually mean?
A star rating is somebody's formula compressing all five numbers into one figure, usually tuned for an average surfer at an average spot. It does not know your ability, your board, or how far you are willing to drive.
Use stars to skim, then look at the numbers. A two-star day at a sheltered beach can be the best session of the week for a beginner, and a four-star day at a heavy reef can be one you should sit out.
How far ahead is a forecast trustworthy?
Swell is predictable several days out because it is generated by storms that already exist and travel at a known speed. Wind is not: it is local, it changes hour to hour, and it is the thing most likely to ruin an otherwise good forecast.
So treat the swell part of a five-day forecast as roughly reliable and the wind part as a guess that firms up inside 48 hours. Check again the morning you plan to surf.
Common questions
Is wave height measured at the face or the back?
Most forecasts report the face height - the part you actually ride. Some regions traditionally quote the back of the wave, which reads about half the size, so a 3 ft Hawaiian reading is a head-high wave.
What wind direction is best for surfing?
Offshore - wind blowing from the land out to sea. It holds the wave face up and makes it clean. Onshore wind blows the wave over early and turns the surface to chop.
Do I need to understand tide?
Only for your spot. Most beach breaks work across the tide; reefs and points often have a narrow window. Learn the pattern at the one or two places you surf and ignore the rest.
Why is the surf report often wrong?
Usually it is not wrong about the ocean - it is describing conditions offshore that the beach you chose could not receive. Local wind is the other common cause.