Three main variables influence the size of waves arriving at the coastline: wind speed, wind duration, and fetch. Is there a way to establish a reasonable and fairly accurate nonlinear correlation between them? Yes, there is.

The table below summarizes typical conditions under which wind generates waves over a consistent fetch.

The fetch is the distance over water that the wind blows in a steady single direction.

So, for each wind speed level featured in the Beaufort scale, the table shows how many hours of sustained blowing are needed for the sea surface to develop waves of a given height.

The chart also includes the corresponding wave period – the time between successive wave crests – which increases as waves become larger and more organized.

Because wave height and wave period depend not only on how strong the wind is but also on how long it acts on the water, the values shown represent approximate, idealized conditions assuming steady, uninterrupted wind over open water.

It’s a simplified theoretical guide, but it accurately reflects reality.

In the ocean and in large enclosed seas or lakes, factors such as changing wind direction and variable fetch can lead to deviations from these theoretical values.

SurferToday has a more detailed, in-depth article on forecasting waves based on wind data. It might be worth taking a look at.

Wind-to-Wave Scale

Therefore, the following table helps you quickly figure out how wind builds waves over time.

You’ll notice that higher wind speeds are required to create sizable waves; weaker winds, no matter how long they blow, will never produce towering waves.

Hurricane-to-Wave Height Table

Below is also a hurricane-to-wave-height table, as hurricanes travel quickly and interact with smaller fetch areas.

Words by Luís MP | Founder of SurferToday.com