If you’ve ever pulled up a surf report and felt lost in the numbers, this is for you. Every forecast boils down to a handful of core readings — swell height, period, direction, wind, and tide — and once you know what each one means, you can tell in seconds whether a spot is worth the drive.

Swell height

This is the size of the waves out at sea, usually measured in feet. It’s a useful starting point, but height alone doesn’t tell the whole story — a 3-foot swell with a long period can break bigger and more powerful than a sloppy 5-foot swell with a short one.

Swell period

Period is the number of seconds between wave crests. Short periods (6–10 seconds) usually mean local wind swell: choppy, disorganized, and quick to fade. Long periods (12+ seconds) mean the swell traveled from a storm far offshore, arriving as clean, powerful, well-organized waves. When you’re scanning a forecast, period is often the number that matters most.

Swell direction

This tells you which way the swell is traveling from, given in compass degrees or a direction like NE or SE. Not every swell direction works at every beach — sandbars, jetties, and the shape of the coastline all favor certain angles. Spend a season at your local break and you’ll start to recognize which direction lines up best.

Wind

Wind shapes the surface of the wave. Offshore wind (blowing from land toward the ocean) holds up the wave face and grooms it clean — this is what surfers wait for. Onshore wind (blowing from the ocean toward land) crumbles waves and makes them choppy. Light or calm wind, especially early in the morning before the day heats up, is usually your best bet for clean conditions.

Tide

Tide stage changes how a wave breaks over the sandbar or reef beneath it. Some spots along the Southeast Atlantic work best at low tide when the sandbars are exposed and waves break with more punch; others need a higher tide to have enough water to break cleanly at all. Tide moves throughout the day, so the same spot can go from firing to flat in a few hours — always check a tide chart alongside the swell forecast.

Putting it together

A good session usually lines up: a swell with decent size and a long period, arriving from a direction your local break likes, with light or offshore wind, at a tide stage that works for that spot. No single number tells you everything — it’s the combination that matters. Check our Regional Surf Reports for live conditions at your favorite Southeast Atlantic spots, and use this guide to make sense of what you’re looking at.