How to read a surf forecast

For those just starting out surfing, reading a surf forecast looks about as simple as translating Morse Code. Learning how to do it, though, is pivotal, because conditions and virtually conditions alone determine when you should surf, and where you should surf. Fortunately, it’s not quite as complicated as it might look initially, and once you decode all the arrows, numbers and colours you’ll wonder what all the fuss was about. In this article, we’ll cover everything you need to know about reading surf forecasts and reports, from why you need to do it, which ones you should be looking at, and most importantly, how to actually do it.

Why is it important?

Surfing is a relatively unique sport in that you can’t just practice it whenever you want – unless you live near a wave pool of course. Depending on where you live and where you surf, conditions can change drastically from day to day, and it’s vital to know what you’re getting yourself into before you head to the beach, and particularly before you head out. 

If you’re just learning, you absolutely do not want to be paddling out in conditions which are beyond your capabilities, so knowing what to expect is key. You might be thinking that you can just look at the ocean and figure it out – that’s true to an extent, but conditions can also change during a session, with rising or ebbing tides, growing or waning swells, and changes in wind directions. Surf forecasts will help to give you an idea of what is going to happen in the water throughout the course of the day, enabling you to both capitalise on the best conditions and avoid those which are either not going to benefit your surfing, or which could potentially be dangerous to you.

What are the best tools to predict sea conditions for surfing?

There are a number of different options you can use to predict sea conditions. Each of them offer a varied experience, and while they will generally provide relatively similar forecasts they won’t always be identical. One of the most common has for a long time been Magic Seaweed, though they were recently purchased by Surfline. 

Surfline is not one I’d used a whole lot in the past, but having now taken over Magic Seaweed – which I previously used – I’ve made the move across. It’s a really comprehensive app and website for surf predictions, and they also offer a whole lot else in terms of news, webcams and much more. From a forecasting perspective, in my experience there’s not too much to complain about, except that the swell predictions tend to be a little larger than what I’m used to from Magic Seaweed. As with all surf forecasters though, once you get used to their predictions you develop an understanding of what sort of conditions certain predictions with a specific app will translate to.

Another website which I use regularly is WindGuru, which is used fairly often among the sailing fraternity. It provides swell predictions, too, but generally I rely on this mostly for winds. I find it to be the most accurate among the surf forecasters that I use in terms of winds, and while the swell is generally pretty spot on with them too I will generally compare that with another app like Surfline.

Another pretty common option is the Windy App, which is commonly used for a variety of water sports, including kitesurfing, windsurfing and so on. This app has a pretty easy interface to use and generally seems to provide good wind forecasts, though I can’t claim to have used it as much as the above two options.

WillyWeather is the final one that I tend to look at a bit, though this is primarily for the wind. The benefit of using this is that they provide predictions of the wind in hourly increments throughout the day, while they also report the wind conditions every couple of hours. This means that if the wind is predicted to turn onshore at about 3pm, and you’re wondering if you’re going to be able to get a surf in after work, you can continually check with WillyWeather to confirm whether the onshores have or have not arrived.

Overall, with Magic Seaweed now having been swallowed up, Surfline is the biggest and most popular surf forecasting modeller out there, and is well and truly worth downloading. It can often be worth complementing the forecasts they provide with another app like WindGuru, particularly for wind predictions, but if you stick to Surfline you’ll generally have a pretty good understanding of what conditions are to come.

Is it free to access surf forecasts?

Generally yes, you will be able to access sufficient information without having to pay. There are, however, options to pay for subscriptions to get more information. With Surfline, for example, the forecasts for today and the next four days are available free of charge, but if you pay for a subscription you’ll be able to get up to 16 days of predicted forecasts – obviously the forecasts 16 days out can be a little bit less reliable, but if you want an idea of what sort of conditions are coming over the next week or so then you’ll need a subscription in this case.

What should I be looking for in a surf forecast?

Now to the nitty gritty – the actual reading of a surf forecast. There are essentially three main things that you need to look for in the forecasts, which we’ll cover individually below.

Swell size and direction

The first thing to take a look at is swell – that thing that makes those waves we like to surf. This one is pretty easy. Whichever surf forecast model you use will provide a prediction of the swell size in metres or feet – be careful not to expect this to translate into wave size though, because it doesn’t. A swell size of 10 feet, for example, doesn’t mean that the waves will be ten feet. How big they will actually be depends on both where you’re surfing, as well as a thing called the period and the swell direction, each of which we’ll look at below. To get the best idea of what sort of wave size different swell sizes correlate to at a certain spot, you’ll basically just need to look at the waves and compare it to the surf forecasts – initially this is tough, but after a few times you’ll get an understanding of what a certain swell size means at your local spot. Modellers like Surfline will provide an estimation of wave size, which can be useful, but they’re generally a bit vague – something like 1-3 feet would be a common estimation.

Now to the period of the swell, which I mentioned above. Alongside the size of the swell you’ll notice a period of time listed in seconds – for example, 15s. This is the period, and in essence refers to how much time will pass between waves within a set. Without going into too much detail about the hows and the whys, all you need to know at this point is that in general, the longer the period, the more powerful the swell. A 6-foot swell at 18 seconds, for example, will likely result in waves a fair bit bigger than a 6-foot swell at 12 seconds. Depending on the spot, a 3-foot swell at 15 seconds could very possibly be bigger than a 6-foot swell at 9 or 10 seconds. 

Finally, to the swell direction. This tells you where the swell is coming from, and can impact both the quality and the size of the waves. Where I surf, the swell generally comes from a south-south-westerly direction – usually, swells which are from a bit closer to south are a little more powerful and will likely have a longer period, while if there’s a bit more west in the swell they don’t quite line up as well and will usually be a little weaker. If it’s coming from a completely different direction, such as south-east, the surf won’t be any good.

Wind

The wind is a little more straightforward than the swell. Your surf forecasters will tell you what the wind is expected to be at intervals throughout the course of the day, and this is key to the quality of the waves that you’ll get. Offshore winds are those which head back out to sea from the land, and light versions of these are optimal for surfing. In contrast, onshore winds come from the sea and will make the surf a mess. 

That’s pretty much all you need to know about the wind. Take a look at which direction it is as well as the strength, and that will tell you a fair bit about what conditions you’re likely to encounter.

Tide

The final thing to look at when trying to decode a surf forecast is the tide. Exactly how much this matters and what it does to the surf depends entirely on the spot; some breaks work best on a high tide, some on a low tide, while some are a bit more resistant to different tides. 

Basically all of the aforementioned surf forecasts will give information about this, telling you what time low tide and high tide will be and providing a graphic of how it’s going to change throughout the day. And these aren’t just predictions – where the swell and wind forecasts aren’t guaranteed to be 100% accurate, the tide times are known, so if you want to surf your local spot at low tide, for example, you’ll know exactly what time that is.

What is the difference between surf forecasts and surf reports?

There are also options out there to access surf reports, as opposed to surf forecasts. As the name suggests here, the difference is that while a forecast is predictive, a report is based on observations. Rather than getting information about what conditions are set to come in the future and then having to decode that, a report simply tells you what the waves are like that day. 

Swellnet is the best example of this. Each morning, they provide observations for a host of different surf locations around the world, with about a paragraph of text describing the conditions. Today, for example, Swellnet has provided the following dawn report: 

“Dawn report: The swell has come up a little but it’s weak and low period so coming in a bit less walled up and not showing much energy on the high tide. Take some volume and expect improving surf as the tide drops, but also we may see the size ebb as well. There’s a wave for the keen. Tune back in for the updated photo report around 8am.”

This was provided, as the name suggests, at dawn, while another was provided an hour or two later at 8am. This is a really valuable tool if you’re looking to go for a surf on a particular day, as essentially the report can confirm how accurate the forecasts were. The forecasts won’t ever be entirely wrong, but for example there may be a big swell expected to arrive the following morning; a report can tell you if it has indeed arrived, or if the waves are still relatively small, meaning the swell hasn’t yet arrived.

Is it free to access surf reports?

Not always. Swellnet, my go to for surf reports, provides the aforementioned reports free of charge – but not as they’re written. If you’re not a subscriber, you’ll have to wait until 9am to see the reports which are often done at around 6:30am. If you’re keen to go for a surf early in the morning, this means you won’t be able to check those reports before you go. 

Fortunately it’s not particularly expensive to sign up – a yearly subscription comes in at $6.66 per month, or $79.95 for the year. This will give you access to these surf reports as they’re written, while you’ll also be able to check out all the surf cams Swellnet has at their disposal – which is plenty – rather than only the select few available for free.

If you’re just starting out, reading a surf forecast can seem like an intimidating prospect. With a little bit of practice, however, you’ll realise that it’s not as difficult as it might have seen. And given how important it is to find surf in conditions that are going to aid your development, being able to read these forecasts, and knowing where to find both them and surf reports, is super important. What’s more, once you’re a more accomplished surfer, your standards for the kinds of waves you want to surf will likely be higher, so knowing when these conditions are going to present will save you a whole lot of driving.