The difference between winter and summer wetsuits

Essentially, the thickness of your wetsuit will determine if it’s for the winter or summer. That shouldn’t really come as a surprise. But just so you know, the thicker the wetsuit (in terms of millimetres) the more suitable it is for colder conditions. The thinner the wetsuit, the more appropriate it is for the summertime.

However, there a couple of subtle features that will indicate whether your wetsuit is winter or summer worthy.

Winter wetsuits

If you’re surfing anywhere that’s cold, you’re going to want a winter wetsuit. Temperatures will vary depending on where you’re surfing, but generally, you’ll start at a 3/2mm and work your way up. However, it’s always important to do a bit of research - as surfing in Australia can be a lot different to surfing in the United Kingdom during winter.

What do the numbers mean?

The first number in the millimetres indicates the thickness found around your torso. For example, a 3/2mm wetsuit will have 3 millimetres of neoprene around your core. The second number in millimetres refers to the amount of neoprene found on the arms and legs of your wetsuit. The reason there is always less neoprene situated on your arms and legs is because it allows for more manoeuvrability and flexibility. And with your core area, it’s thicker because your vital organs need to be protected, so your body will allow more heat for your limbs. It's one of those biology things.

What seams are commonly found in winter wetsuits?

Glued and Blindstitched (GBS) and Fluid Sealed are often found on a winter wetsuit. A GBS seam works by not completely penetrating through both sides of the neoprene, creating a completely watertight durable seam. A Fluid Sealed seam (often referred to as Liquid Taped) is the ultimate seal whereby a special liquid rubber is applied to the inside seam, making it 100% waterproof.

You will never find a 4mm wetsuit and upwards in anything less than GBS. The reason for this is the following:

- GBS is waterproof thanks to the glue ensuring cold water doesn’t come in.

- The thickness of the wetsuit determines what stitch/seam you can actually use. It’s hard to manufacture GBS on a wetsuit less than 3mm because the stitch only goes halfway through and the neoprene is so thin. Likewise with Flatlock Stitching on 4mm wetsuits and upwards, as you have to stitch all the way through a lot of thick neoprene.

Additionally, you will often see a wetsuit (both winter and summer) that uses more than one seam. For example, you might find a wetsuit that is GBS in the arms but Fluid Sealed in the core and legs. This is because of the amount of neoprene used for both, as mentioned previously. It allows a wetsuit to be durable and flexible where it needs to be.

What lining is found in winter wetsuits?

The lining inside a wetsuit is one of the areas that has seen the greatest technical development in the last few years, making them much warmer, more comfortable and faster drying. Some brands such as Rip Curl, Billabong and Quiksilver boast iconic linings for their wetsuit range that are updated to incorporate the latest in warmth technology (Flash Lining/Furnace Lining/WarmFlight Infared respectively), whilst others simply opt for a standard lining that still performs. As you may have guessed, winter wetsuits will normally have some sort of thermal lining, whereas summer wetsuits do not always. Thus, there are a couple of key factors to consider:


As mentioned, linings vary a lot and brand ranges will normally contain 2-3 types of lining from entry-level to high-end. At the most basic a thermal lining will be made of Hollow Fibre/Polypro, essentially synthetic fibre that retains some of the warm air your body creates and traps it there. These are warm but can be restrictive and get heavy when wet. At the other end of the scale, you are likely to find a ‘Plush’ lining, which will be fluffier to trap more warm air and take water away from the skin, more flexible, better at draining water out (less water retention) and dries more quickly.


An easy one to understand, the more coverage of the thermal lining inside the suit the warmer you’ll be overall! Entry-level winter suits and summer suits often only have lining on chest/back panels, high-end cover chest to ankle or even the entire inside!

Please note: O’Neill is a bit of an exception when it comes to thermal linings; high-end suits do not have a plush lining but rather use bigger air bubbles in the actual neoprene for added warmth and then use a hydrophobic layer of nylon inside the suit to evacuate unwanted cold water.


Things to remember when looking at a winter wetsuit:

- Start at a 3/2mm and work your way up.

- Make sure the seam is going to be strong enough.

- Less neoprene in the arms and legs as well as a different seam to allow for extended movement.

Summer wetsuits

It’s almost an oxymoron the term ‘summer wetsuit’ but the truth is a summer wetsuit is just as important as its wintery counterpart.

Where a winter wetsuit starts at 3/2mm, a summer wetsuit will end there. There are a lot of countries in the world where a summer wetsuit is not needed. However, if you live somewhere cold, you may not have the luxury of paddling out in your bathers.

Therefore, your options are:

- Shorty wetsuits

- 2mm wetsuits

- 3mm wetsuits

A shorty wetsuit is generally short in the arm and leg. However, it can come without arms (short John) or with long arms. It’s really a matter of preference, and also how cold the temperature is (both outside and water).

There reason you don’t want to wear anything above a 3mm in the summer, is because you’ll overheat and exhaust yourself. The thicker the wetsuit is, the heavier it is, and that contributes to your body weight. If you’re weighing more than you need to in the water on a hot day, it’s going to affect your paddling. If you’ve ever surfed in just boardshorts or a bikini, you’ll understand how much easier it is to manoeuvre yourself over a long period of time.

The thinner your wetsuit is, the more flexible it’s going to be. So if you can get away with wearing a 2mm wetsuit, you’ll still feel a lot of freedom around your arms and legs. Additionally, a wetsuit can protect your chest from grazing on your surfboard – the same way a rash vest or wetsuit top works. You might also find that wearing a wetsuit can protect your body from the sun.

What seams are commonly found in summer wetsuits?

The stitching will vary across all summer wetsuits. Traditionally, you will find Flatlock Stitching on a summer wetsuit, as well as GBS in the higher-end wetsuits. Flatlock Stitching is also glued to make it as watertight as possible, however, due to the nature of the stitching, water will often enter and exit the wetsuit. This isn’t necessarily a bad thing, given the outside and water temperature will be warm, as you’ve opted for a summer wetsuit.


Things to remember when looking at a summer wetsuit:

- Don’t go above 3/2mm.

- The thinner it is, the more flexible it will be.

- Personal preference in terms of short arms, long arms or short John style when purchasing a ‘shorty’ wetsuit.

- Summer wetsuits can protect you from the elements, whilst not restricting your surfing session.


Wearing a wetsuit will always be determined by the weather. Just because it might be 'winter' somewhere doesn't mean it's going to be cold. The Triple Crown is kicking off in Hawaii and it's technically winter over there, but guaranteed you will not see one professional surfer wearing a 'steamer'. Instead, you will see boardshorts, shorties and wetsuit tops.

For more information on what you should be wearing for where you are in the world, read our blog 'Wetsuits for Global Destinations' here.


Shop our full range of wetsuits here.



Published on 29th October 2018 in Windsurfing


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