What is swell period?
Swell period is the time, in seconds, between one wave crest and the next passing the same point. Longer periods mean more energy: a long-period swell of the same height breaks bigger and more powerfully than a short-period one.
Last updated · Surf & waves glossary
About Swell period
Forecasts list period next to height for this reason. Short-period swells are usually local wind swell; long-period swells are groundswell from distant storms.
- Also called
- wave period
Related terms
- Groundswell
- Groundswell is swell generated by distant storms that has travelled a long way across the ocean, arriving as long-period, well-organised waves. It is the opposite of wind swell, which is made by local winds.
- Swell direction
- Swell direction is the compass direction a swell comes from. Each break works best on the swell directions that reach it unblocked and hit its reef, point or sandbar at the right angle.