Basic Guide: How Do Waves Work in Hawaii?

General view of Pipeline in Hawaii, December 20, 2013. Photo: Ryan Miller / Red Bull Content Pool

Surfing in Hawaii is one of the most incredible and powerful experiences in the world because, unlike other countries, waves here don’t depend only on local wind, but on swells that travel thousands of kilometers across the Pacific Ocean. However, to understand the forecast, it’s necessary to learn how to read several key elements.

When checking a surf forecast, one of the most important concepts you’ll see is swell, as it makes the difference between finding good waves or arriving at the ocean in poor conditions. This concept refers to a group of waves that form far from the coast, usually due to storms or strong wind systems in the ocean, and travel long distances across the sea until reaching different coasts around the world.

Unlike waves generated by local wind, swells tend to be more organized, clean, powerful, and consistent. That’s why when surfers say “swell is coming,” it usually means good surfing conditions are expected. In Hawaii’s case, the islands receive waves from both hemispheres, something unique that allows surfing year-round.

Kai Lenny watching the ocean in Hawaii. Photo: Marc Chambers / Red Bull Content Pool

During winter, between October and March, North Pacific swells generate bigger and more powerful waves, mainly activating the North Shore with spots like Banzai Pipeline, Sunset Beach, and Waimea Bay. In contrast, during summer, between May and September, South Pacific swells produce softer and longer waves with better conditions on the South Shore, in places like Waikiki Beach and Ala Moana Bowls.

The same swell can generate large waves on one coast and almost nothing on another. Therefore, direction is also fundamental, since each beach works with different orientations. For example, north and northwest swells usually favor the North Shore, while south and southwest directions generate better conditions on the South Shore.

Another important element is the period, which indicates the time between waves and helps understand ocean quality. When the period is low, waves tend to be weaker and less organized. On the other hand, when it exceeds 12 seconds, the swell begins to gain strength, and above 15 seconds it is considered a powerful swell — something quite common in Hawaii. The longer the period, the more energy the waves carry, directly influencing their size and power.

A competitor surfing during the Red Bull Magnitude event at Waimea Bay, Oahu, Hawaii, USA, January 16, 2021. Photo: Christa Funk / Red Bull Content Pool

Tides also influence wave behavior, as each spot works differently depending on sea level. In general, high tide tends to produce softer waves, while low tide creates faster and more hollow waves. Wind is another key factor that can improve or ruin surf conditions.

For example, when the ocean is glassy, it means there is no wind and conditions are ideal. If the wind blows from land to sea, known as offshore, waves tend to improve. On the other hand, crosswinds create irregular waves, and onshore wind, which blows from the ocean toward the coast, usually worsens surf quality.

An empty wave at Banzai Pipeline during the Volcom Pipe Pro in Oahu, Hawaii, USA, February 1, 2020. Photo: Zak Noyle / Red Bull Content Pool

In Hawaii, mornings often offer better conditions due to lighter winds. To find good waves, surfers typically check apps like Surfline, Windguru, or Surf Forecast, looking for a high period, favorable direction, light wind, good energy, and suitable tides.

When these factors align, it’s more likely to find good conditions. For greater accuracy, many surfers check the seven-day forecast to plan ahead and then confirm with the 48-hour forecast, which is usually more precise. This combination helps anticipate incoming swells and choose the best time to enter the water.