How to read a surf forecast
on Surfline for beginners
Lesson 6
Post contents
Introduction
Surfers around the world know that understanding how to read a surf forecast is the key to picking the right place and time to go surfing. Grasping how to interpret the details in surf forecasts is a must. In this lesson, we’ll dig into the essentials of how to read a surf forecast and introduce you to the best surf forecast app to help you time your surfing sessions just right.
What is a surf forecast?
Before we jump into the specifics of how to read a surf forecast, let’s start with the fundamentals of what a surf forecast is and why it matters. A surf forecast is essentially a weather report for waves, providing valuable information on upcoming wave conditions. Surf forecasts include data on swell conditions, wind conditions, tides, and more. These factors combined can help you determine when and where to hit the waves. Learn how to read a surf forecast to ensure you don’t end up at the beach when the waves are either disappointingly flat or dangerously large, especially if you’re a beginner.
What is the best surf forecast app?
Determining what is the best surf forecast app can be subjective, as it often depends on individual preferences and needs. However, one of the top surf forecast apps that is highly regarded by surfers is the Surfline app (reports and forecasts are also accessible through their website). In this lesson I will use the Surfline website to demonstrate how to read a surf forecast as a beginner.
The basics and beyond the basics of a surf forecast for beginners
A surf forecast consists of a few different components which will help you understand if it’s a good or a bad day (and time of day) to surf. It’s easy to get overwhelmed when you’re new to surf forecasting, with all the different components that exist.
Therefore, in this guide, I have split the components between “the basic” components and “beyond the basic” components. If you think it’s too much to grasp at once, I recommend that you start with understanding “the basic” components, and gradually also start to learn “beyond the basic” components.
What are the components that make up a surf forecast?
The basics
What makes up the basics of a surf forecast in my opinion is the tide, surf height, and wind conditions. Aim to understand these components first. I will also go over the rating as a basic component, although I would say you should not rely too much on the rating.
1. Rating
The rating on Surfline is Surfline’s own rating of the surf conditions, made to their best extent. Surfline rates the conditions of the spots available in the app/their website to give you an indication of whether it’s a good or bad day (and time of day) to surf. You can see what ratings exist and their corresponding colors in the picture below:
On Surfline, the ratings are shown in the “Report & Forecast” tab view of a chosen surf spot (we will look more at how you find this view later on in this guide). It looks like in the picture below:
Why should I not blindly trust the Surfline ratings?
The ratings are calculated and set based on a few different factors which you can read more about here. Let’s take the surf height as an example of why ‘poor’ doesn’t always mean poor conditions, and ‘good’ doesn’t guarantee good conditions. Wave height is one of the factors used to set the rating, and different people like different wave heights- it’s subjective. A beginner surfer probably prefers a a smaller wave height, while a more experienced surfer might value a bigger wave height.
Therefore it’s not really possible to provide a rating that fits everyone, because everyone have different preferences. While the rating can give a good indication in many cases, I recommend that you don’t blindly “trust” the ratings provided by Surfline. They might be perfect for one surfer but not very accurate for another surfer.
What should I do instead?
Learn how to read a surf forecast, by looking at the tide, surf height, and wind in the forecast- this is exactly what you will learn how to do later in this guide. Eventually, you can also start looking at the primary swell and secondary swell conditions, as you become more familiar with reading surf forecasts. I also recommend that you aim to learn what types of conditions you personally prefer, because personal preference is a key factor in finding the best conditions for you based on your skill level and style. Of course this can very depending on what spot you surf at since every spot is unique.
To figure this out, start by noting down details after each surf session: the beach you visited, the conditions that day (tide, surf height, and wind, and eventually also primary swell and secondary swell), and your thoughts about them- did you enjoy them or not, and why? Over time, you’ll begin to understand which conditions suit you best at specific spots.
To help you out a bit I have provided general recommendations under the headline “What are the best conditions per component in general?“, but over time I strongly recommend that you figure out the conditions that work best for you personally.
2. Tide
Tides are the movement of the ocean water going up and down. It’s about how high or low the water is at different times of the day. This is an important part of learning how to read a surf forecast- especially if you will be surfing at reef breaks. Tides affect the surf by changing how waves break. Waves form when ocean energy (swell) moves from deep water to shallow water, hitting sandbanks or reefs on the sea floor.
At high tide, there’s more water over the sandbanks or reef, making the waves slower and softer, often called “fat” or “lumpy.”
At low tide, with less water covering the sea floor, waves break faster and steeper, sometimes feeling “dumpy” or more intense. Tides also affect safety- for example, reef spots can be riskier at low tide because the shallow water makes hitting the reef more likely.
Some surf spots work better when the tide is higher, and some work better when the tide is lower. On Surfline, the tide is shown in the “Report & Forecast” tab view of a chosen surf spot (we will look more at how you find this view later on in this guide). It looks like in the picture below:
In the chart, when the curve reaches its peak, it signifies high tide. When the curve is at its lowest point, it indicates low tide.
3. Surf height
The Surfline surf height is an estimate of the size of the waves when they arrive to the shore, specifically how tall they are. It should not be confused with the swell height, because that is something different- swell height is rather the average height of the wave out at sea.
On Surfline, the surf height is shown in the “Report & Forecast” tab view of a chosen surf spot (we will look more at how you find this view later on in this guide). It looks like in the picture below:
What different surf height metrics can I choose between on Surfline?
You can select between three different surf height metrics in the Surfline app and website. Which metric you choose depends on your own preference. I recommend that you choose the metric “Feet (Face Height)“. This is the default metric set by Surfline for all countries except for Australia and New Zealand. It’s also the metric I will be using throughout this guide.
Below is a short explanation of the different metrics you can choose between:
- Face Height: Measures the face (front) of a wave, from top to bottom.
- Traditional/Hawaiian: Equates to roughly half the face height. There are different theories as to why this measurement was introduced- one of them is that this is a measurement of the back of the wave which is usually about half the height of the face of the wave.
- Meters: Reports wave height in meters instead of feet.
You can read more about the metrics and how to change the metrics here.
How does Surfline determine the surf height?
Surfline provides an approximate, average surf height by using the metrics swell height, swell period and swell direction in their calculations. You can read more about how calculations are made and the difference between surf height and swell height on Surfline here.
By default, Surfline reports the surf height in the metric called “Face Height” for all countries except Australia and New Zealand. So, the measurement is of the face (front) of a wave, from top to bottom like in the picture below:
What is the Surfline face height scale?
The Surfline face height scale translates feet into “body part height”, making it easier for surfers to understand how tall the wave is. As described on their website, it’s based on the assumption that a surfer riding a wave would have slightly bent knees. This is the Surfline face height scale:
- 1′ = ankle-shin high
- 2′ = knee-thigh high
- 3′ = waist-belly high
- 4′ = chest-shoulder high
- 5′ = head high
- 6′ = 1 foot overhead
- 8′ = 3’overhead
- 10′ = 5′ overhead or Double Overhead faces
- 12′ = Double Overhead+ faces
- 15′ = Triple Overhead faces
- 20′ = It’s just really big
Exactly how Surfline calculates the surf height is described here.
4. Wind
Wind is another important factor in surfing and learning how to read a surf forecast. What you should pay attention to is the wind speed and the wind direction. On Surfline, the wind is shown in the “Report & Forecast” tab view of a chosen surf spot (we will look more at how you find this view later on in this guide). Under “Wind” you can see the wind speed, followed by the wind direction. It looks like in the picture below:
4.1. Wind speed
The wind speed measures how fast the wind is blowing. There are different metrics which wind speed is reported in on Surfline, including kilometers per hour (kph), miles per hours (mph), and knots (kts). You can choose your preferred metric in your account settings. In this guide I am using knots (kts) when demonstrating how to read a surf forecast.
Wind speed affects the surf by influencing how smooth or rough the waves are. In general, light winds create clean, glassy waves, while strong winds can make the waves choppy and harder to ride.
4.2. Wind direction
The wind direction indicates where the wind is coming from (not what direction the wind is blowing towards). It plays a key role in wave shape.
In general, offshore winds (blowing from land to sea) help smooth the waves and make them break more predictably.
In general, onshore winds (blowing from sea to land) make the waves messy and can cause them to break unevenly, making surfing more challenging.
Beyond the basics
You might go out surfing one day and think the conditions are perfect for you when you have looked at the tide, surf height, and wind conditions. Then, you might go out surfing another day when the tide, surf height, and wind conditions are exactly the same as last time, but the surf is not as good as last time.
While looking only at the tide, surf height, and wind conditions is a good start for beginners, eventually, you should also start looking at swell conditions: swell height, swell period, swell direction, and secondary swell. These factors can significantly impact the surf conditions.
The reason I am saying this is “beyond the basics” is because I think it can be overwhelming to dive into all these details when you’re just starting out. However, as you gain more experience, understanding these additional components will help you better predict surf quality and choose the best days to head out for you. It’s a gradual learning process, so don’t feel pressured to master everything right away.
5. Primary swell
Primary swell refers to the main swell that creates the majority of the waves. It includes swell height, swell period, and swell direction.
5.1. Swell height
Swell height is measured out at sea, where the swell originates. This is how large the average wave is before it reaches the shore. It should not be confused with surf height- surf height is rather the size of the wave when it reaches the shore.
On Surfline, the swell height is shown in the “Report & Forecast” tab view of a chosen surf spot (we will look more at how you find this view later on in this guide). It looks like in the picture below:
5.2. Swell period
The swell period is the time between waves, measured in seconds. Longer swell periods usually mean bigger, more powerful and better-quality waves. Shorter swell periods can result in smaller and less powerful waves.
On Surfline, the swell period is shown in the “Report & Forecast” tab view of a chosen surf spot (we will look more at how you find this view later on in this guide). It looks like in the picture below:
5.3. Swell direction
The swell direction indicates where the swell is coming from (not in what direction the swell is travelling to). Knowing the direction from which the swell is coming helps you predict how the swell will hit your surf spot and thereby also how the waves will break.
On Surfline, the swell direction is shown in the “Report & Forecast” tab view of a chosen surf spot (we will look more at how you find this view later on in this guide). It looks like in the picture below:
6. Secondary swell
The secondary swell on Surfline shows up to two additional swells that can also influence the surfing conditions. The secondary swell is usually less significant than the primary swell, but it helps provide a more complete picture of surf conditions, as the secondary swell can interact with the primary swell to create different wave patterns.
On Surfline, the secondary swell is shown in the “Report & Forecast” tab view of a chosen surf spot (we will look more at how you find this view later on in this guide). It looks like in the picture below:
What are the best conditions per component in general?
There is no one-size-fits-all answer when it comes to surf conditions, because every surf spot is unique and everyone has different preferences for what makes the best conditions for them.
The best conditions are always a mix of different components (tide, surf height, wind, primary swell, and secondary swell) and can vary from spot to spot and person to person. The ideal wind, for example, might generally be offshore, but if the wind is light, onshore winds can actually work well too.
While I can provide general recommendations, it’s important to remember that these should not be followed blindly, as the ideal conditions are highly dependent on the mix of conditions, the spot, and the surfer.
The best wind conditions in general
Mornings are usually the best
Wind conditions tend to often be the best in the morning, at least at warmer and tropical destinations. That’s because afternoons tend to get more windy, and generally you want light winds.
Offshore wind direction is generally the best
Offshore wind is generally (not always, check your spot’s ideal conditions!) considered the most favourable wind condition for surfing. Offshore wind helps hold up the wave and creates clean and organized waves. Onshore wind on the other hand tends to lead to messy and choppy waves which are harder and not as fun to surf. They also make it harder to paddle out to the lineup I think, as you have to work against the wind, which often splashes water into your face and pushes you around with the choppiness.
Light wind (with a speed up to 10kts) is usually the best
In general (again, check your spot’s ideal conditions!), light offshore winds up to around 10 knots (kts) are often considered ideal for most spots. However, it’s important to note that the best wind speed can vary depending on the specific surf spot and local conditions. For example, at my local surf spot in Sweden it has to be very windy (almost a storm) for waves to even be created- light winds will not work at my local surf spot because then it will just be completely flat!
The best surf height for beginners in general
A good surf height for beginners is 1-3ft using the Surfline face height scale. That translates into the following “body part heights” when your knees are bent:
- 1′ = ankle-shin high
- 2′ = knee-thigh high
- 3′ = waist-belly high
Again, this can vary per surf spot so take this as a general recommendation. Sometimes Surfline can say the surf height at a surf spot is for example 3ft when in fact it might be a bit more or a bit less. So, at some surf spots, when Surfline says the surf height is over 3ft it could still be suitable for beginners.
What about the other components?
This is so so dependent on the surf spot, so it’s hard to give general recommendations. What I can say is that when it comes to tide conditions you should avoid surfing during low tide at certain reef surf breaks. This is because the reef gets exposed during low tide and there’s a high risk of injuring yourself if you hit the reef.
Another thing worth mentioning is that longer swell periods tend to create bigger and more powerful waves, so as a beginner you might want to avoid longer swell periods. But again, what the conditions will look like is so very dependent on the rest of the components’ conditions on the surf forecast and the specific spot you plan to surf at. So, just take this as a general recommendation and not a hard-and-fast rule.
Always consider the full forecast as a whole, rather than evaluating each component in isolation. It’s important to keep learning and adapting your approach based on the conditions you encounter and your own experience level.
How to read a surf forecast using the Surfline website
1. Choose the metrics you want to use for each component in your account settings
The first step of learning how to read a surf forecast using Surfline is to choose what metrics you want the surf conditions to be displayed in. Surfline has set the default metrics and you don’t have to change them, but I at least recommend that you go into your settings and check what those metrics are. You can check your settings and change them on surfline.com/settings.
These are the metric settings I have which I will also use and refer to in this guide:
2. Learn what the ideal surfing conditions are at your surf spot
Every surf spot is unique
Next you need to learn how to find the ideal surf conditions. One very important thing to note is that every spot is different and will have different requirements on what determines the best surf condition for that specific spot. You will need to do some research to figure out what the best conditions are at the specific spot you want to surf at. There are different ways to figure this out.
What you should look for
As a beginner, I recommend that you figure out the following for your surf spot:
- The best tide conditions
- The best surf height
- The best wind conditions
You can (and should eventually) also look at the primary swell and the secondary swell. However, when you’re just starting out I think checking the tide, surf height and wind conditions is enough- otherwise you might become overwhelmed. Overtime you can start to also look at the primary swell and the secondary swell.
In the example I will go over in this guide when showing you how to read a surf forecast, I will only cover the tide, surf height and wind conditions for the sake of simplicity.
Check if you can find the ideal surf conditions on Surfline
One way to understand what the best conditions are at a specific surf spot is to visit Surfline’s website and search for the spot in the search bar on the top of the page. In this example we are searching for the spot Kuta Beach in Bali, Indonesia:
Once you have selected a spot, open the Guide tab. In this tab you can find information about the ideal surf conditions at the spot, including ideal tide, surf height, and wind which is what you should be looking at as a beginner. This page also includes other useful information, such as general information about the spot, ability levels, crowd, water quality, hazards, bottom, best season, and more:
Can't find the ideal surf conditions on Surfline? Try other websites or ask someone.
Unfortunately, not all spots on Surfline’s website have guide information. If you cannot find guide information about a specific spot on Surfline, try other online sites such as wannaSurf, local Facebook surf groups, or ask a local surfer or surf school.
Don't forget to consider your own personal preferences
As I mentioned a bit earlier in this guide, the best conditions at a certain spot also comes down to your personal preference. Conditions that an experienced surfer loves, might not at all be the same conditions that a beginner surfer prefer at the very same spot. That’s why I recommend that you go surfing at a spot a few times and read the surf forecast each time to learn what conditions work well and not for you– maybe even note down what the conditions were during each of your surf sessions so that you don’t forget what you liked and not, using a surf journal.
3. Check the tide conditions
Now that you know the ideal surf conditions for your spot, let’s take a look at how to check if the spot has these conditions in its forecast, starting with the tide conditions. Open the Report & Forecast tab, expand the day you are interested in checking the forecast for, and scroll down to the tides section.
In the chart, when the curve reaches its peak, it signifies high tide. When the curve is at its lowest point, it indicates low tide:
Tide conditions in our example (Kuta Beach)
What are the ideal tide conditions at Kuta Beach?
In step 2 we learned that the best tide conditions at Kuta Beach are “Incoming, medium to high“.
At what time today will the ideal tide conditions occur?
The low tide today is at 7:13am, and the high tide is at 1:54pm. We can see in the forecast that the tide is mid-high a bit after 10:30am and it rises all the way until the highest tide of the day at 1:54pm. That means that surfing somewhere between 10:30am and 1:54pm will be the best time if we only take the tide conditions into account and no personal preferences into account.
How can personal preference be weighed in here?
I also happen to know from personal experience that I, when I was a complete beginner surfer, would prefer surfing a bit before mid-tide would arrive at this specific spot. If deciding time of day solely based on tide I would probably have chosen to be at Kuta Beach between 9:30am to 11:30am. Reason being that surfing white water at Kuta Beach (which you often do as a beginner) is harder when the tide gets higher. When the tide gets higher at Kuta Beach, the waves break closer to the beach. That can be quite scary as a beginner because you’re so close to the beach that you risk hitting the sand if you fall or get pushed by the waves.
4. Check the surf height
The next step of how to read a surf forecast is to check the surf height. It should not be confused with the swell height which is something different. You can read more about the difference between surf height and swell height in Surfline here.
To check the surf height on the Surfline website, open the Report & Forecast tab and scroll down to the day you are interested in checking the surf forecast for. You can also expand the section if desired. Under “Surf (ft)” you can see the surf height.
Surf height in our example (Kuta Beach)
What is the ideal surf height at Kuta Beach and how can personal preference be weighed in here?
At what time today will the ideal (beginner) surf height occur?
5. Check the wind conditions
To check the wind conditions on the Surfline website, open the Report & Forecast tab and scroll down to the day you are interested in checking the surf forecast for. You can also expand the section if desired. Under “Wind” you can see the wind speed, followed by the wind direction.
Wind conditions in our example (Kuta Beach)
What are the ideal wind conditions at Kuta Beach?
At what time today will the ideal wind conditions occur?
How can personal preference be weighed in here?
6. Putting it all together: Tide conditions, surf height and wind conditions
So far, we have looked at each condition including tide, surf height, and wind separately. Now, it’s time to tie it all together. Let’s check if there is a time during the day today in the forecast for Kuta Beach, which fulfils all ideal conditions.
This is what we concluded in the previous steps:
- The best tide conditions will occur between 10:30-1:54pm.
- The surf height will be good for beginners the whole day.
- The wind conditions will be ideal until noon.
This means that from 10:30 to noon is probably the best time to surf at Kuta Beach if you’re a beginner today, because this time fulfils all ideal conditions. However, as mentioned earlier, you should also take your personal preferences into account which you will learn overtime by tracking your surf sessions and the conditions during your sessions in a surf journal.
If you surf white water, perfect conditions become less important
When you’re starting out and focusing on surfing white water (the broken waves closer to shore), having “perfect” surf conditions isn’t as critical. Unlike unbroken waves, which require just the right combination of tide, height, and wind to be more easy to ride, white water forms naturally as waves break and roll toward the shore. This consistency means beginner surfers can practice their skills even on days when conditions aren’t ideal for more advanced surfers.
However, some factors still matter, even for white water surfers:
Tide conditions
Pay attention to the tide, especially at shallow or reef-bottom spots. If the tide is too low, you risk injury from sharp rocks or reef beneath the water.
Wave presence
Even for white water, there needs to be enough wave energy to create consistent white water to practice on. In some spots, light wind won’t produce enough swell, so mild stormy conditions may actually work in your favor.
By understanding these basics, you can confidently plan your white water surf sessions without stressing over “perfect” forecasts. As you improve, you’ll naturally start paying more attention to factors like wind direction or wave height, but for now, simply having white water to ride is enough to get you started if you’re new to surfing.
Summary on how to read a surf forecast
Here’s a summarized checklist of how to read a surf forecast as a beginner surfer and what you should think about.
- Check what the ideal conditions are at your surf spot, including tide, surf height, and wind. The ideal tide varies per spot. The ideal wind is usually light offshore winds, up to 10 knots (kts) but it can differ per spot. A good surf height for beginners is 1-3ft using the Surfline face height scale (up to 1 meter).
- As a beginner, focusing on tide, surf height, and wind is a great start, but over time, you'll benefit from learning about swell conditions too including: swell height, swell period, swell direction, and secondary swell. This will help you better predict surf quality. Take it step by step- there’s no rush to master everything at once!
- Check when (and if) during the day the ideal tide, surf height, and wind conditions (and eventually also primary and secondary swell conditions) will occur. That's the time of day you should aim to surf.
- Don't always trust the Surfline ratings- they are subjective and might not be accurate for everyone. Instead, check the tide, surf height, and wind (and eventually also the primary and secondary swell) to make your own assessment and rating.
- Understand your personal preferences. Log you surf sessions in a surf journal, and note down what the conditions were when you surfed and what you thought about the conditions. This will help you learn what types of conditions you like to surf in.
- When surfing white water, perfect conditions don’t matter much, but you should check the tide for safety and ensure there’s enough wave energy producing waves.
Lesson quiz: test your knowledge
I’d love to hear your thoughts on this post! Whether you have suggestions for improvement, want to share what you liked, or have any questions, feel free to leave a comment below. Your feedback helps me create better content for all aspiring surfers!