The short answer: humid air doesn't damage your curls - it swells them. Hair that is already well hydrated absorbs less moisture from the air and holds its shape; hair that is dry and porous drinks it in and frizzes. So an Australian summer routine is less about sealing hair off from the weather and more about making sure it isn't thirsty in the first place.
From October through to March, most of Australia's east coast sits somewhere between warm and genuinely tropical. Add salt water, chlorine, longer sun exposure and a fan running overnight, and hair that behaved perfectly in July starts doing something else entirely. Here is what is actually happening, and what to change.
Why humidity frizzes curly and wavy hair
Each strand of hair holds its shape through bonds inside the keratin structure. Some of those - hydrogen bonds - are temporary, and water breaks and reforms them. That is why hair reshapes when wet and sets as it dries.
Humid air is full of water. When the air holds more moisture than your hair does, moisture moves into the strand, the cuticle lifts, and those temporary bonds reform in new positions. On straight hair that reads as puffiness. On curly and wavy hair it reads as frizz, because the curl pattern breaks up unevenly along the length.
The important part is the gradient. Hair that is already well moisturised has less room to absorb, so less changes. Hair that is dry, or whose cuticle is roughened by heat, bleach or a stripping shampoo, absorbs quickly and unevenly and frizzes far more in exactly the same weather.
Frizz is usually thirst, not weather
This is the part most summer hair advice skips. Frizz is treated as something to fight with a stronger product, when it is usually a signal that the hair is dehydrated and its cuticle isn't lying flat.
The three most common causes, in order:
- The shampoo is too stripping. Sulphate detergents remove the hair's own lipid layer along with the dirt. Curly and wavy hair is drier to begin with - the natural oils travel down a spiral more slowly than a straight shaft - so it feels the loss first.
- Not enough conditioner, or the wrong placement. Curly hair generally needs more conditioner than straight hair, and needs it concentrated through the mid-lengths and ends rather than at the roots.
- Heat and friction. Hot water, hot tools, rough towels and cotton pillowcases all roughen the cuticle, and a roughened cuticle absorbs unevenly.
Fix the hydration and the humidity becomes far less dramatic. That is the whole strategy.
Find your porosity first
Porosity describes how readily your hair takes up and loses moisture. It is the single most useful thing to know before changing a routine, because it determines how much product your hair actually wants.
The commonly used float test is a rough guide rather than a laboratory measure, but it is free and takes a minute: drop a clean, product-free strand into a glass of room-temperature water and leave it for two to four minutes.
Low porosity - the strand floats
A tightly closed cuticle. Moisture struggles to get in, and products tend to sit on the surface and build up. Use lighter layers, apply to damp rather than soaking hair, and let warmth help - a treatment applied in a warm shower absorbs better than one applied in a cold bathroom.
Medium porosity - the strand sinks slowly
The easiest to work with. A standard cleanse, condition and light oil routine is usually enough, with a weekly treatment through the hotter months.
High porosity - the strand sinks quickly
A raised or damaged cuticle, common after colour, bleach or years of heat styling. It absorbs fast and loses moisture just as fast, which is why high-porosity hair frizzes hardest in humidity. It wants richer layers, more frequent treatments, and something to smooth the cuticle after washing.
The summer routine, in order
1. Cleanse less often, and more gently
Most curly and wavy hair does not need washing daily, and in summer the instinct to wash more after beach days and sweat works against you. Two to three times a week suits most people. Between washes, rinse with plain water and re-condition the ends rather than running a full cleanse.
Choose a sulphate-free formula. Our Extra Hydrating Natural Shampoo with Lemon Myrtle and Emu Apple is made for normal to dry, thick, coarse or colour-treated hair; if your waves are fine and get weighed down easily, the lighter Extra Gentle Natural Shampoo is the better starting point. If you are coming off a conventional shampoo, it is worth reading what actually happens in the first six weeks before you judge the results.
2. Condition generously, from the mid-lengths down
Use more than feels reasonable, keep it off the scalp, and comb it through with your fingers or a wide-tooth comb while it is in. That combing step is where curl clumps form - skip it and the pattern breaks up as it dries.
Our Extra Hydrating Natural Conditioner is silicone-free, which matters here: silicones smooth the surface immediately but build up over time, and that build-up is a common reason curls slowly lose definition over a season. The Extra Hydrating duo pairs the two.
3. Rinse cool, and rinse longer than feels necessary
A cooler final rinse helps the cuticle lie flatter. Under-rinsing is one of the most common causes of dull, heavy summer hair, and it takes longer than most people allow.
4. Add oil to wet hair, not dry
This is the step that changes the most. Oil applied to soaking-wet hair helps hold the water already in the strand rather than trying to add moisture later. A few drops through the mid-lengths and ends is enough.
Our Kakadu Plum Scalp & Hair Oil is formulated for thick, frizzy, dry, curly or coarse hair. If you have fine waves, use less than you think and keep it to the ends only.
5. Dry gently, and stop touching it
Squeeze - never rub - with a microfibre towel or a cotton T-shirt. Then leave it alone. Handling hair while it dries is the single fastest way to create frizz, because it disturbs the bonds while they are still setting.
6. Treat weekly through the hot months
A weekly mask does more for summer frizz than any styling product. Our Deep Nourishing Hair Treatment Mask - a Gold winner at the Clean + Conscious Awards - is designed for this, and there is a fuller method in how to use a natural hair mask for maximum results.
Sulphates, silicones and the curly girl rules
The curly girl method has helped a great many people, and it also carries a lot of folklore. Sorting the two is worth doing.
Worth following: avoiding harsh sulphate detergents, conditioning far more than you think you need, combing conditioner through while wet, and drying without friction. These address the actual mechanism.
Worth questioning: the idea that every silicone and every sulphate is harmful in all circumstances, that shampoo must be abandoned entirely, and that one routine suits every curl pattern and porosity. Fine, low-porosity waves and coarse, high-porosity coils want quite different things.
Our own position is simple enough: we leave sulphates, silicones and synthetic fragrance out because they work against the hydration strategy above, not because a rule says so. If you want the ingredient-by-ingredient version, our guide to reading a shampoo label in Australia goes through it.
Where you live changes what your hair does
Two people can follow the same routine and get different results, and geography explains much of it.
- The Northern Rivers, south-east Queensland and the tropics. High humidity for months at a time. Prioritise hydration and weekly treatments, and accept a little movement rather than fighting for a sleek finish that the air will undo anyway.
- Perth, Adelaide and parts of regional Australia. Harder water in many areas. Dissolved calcium and magnesium leave a fine film on the hair that reads as dull and straw-like. A fortnightly apple cider vinegar rinse - one tablespoon in a cup of water - helps, as does a longer rinse.
- Anywhere coastal. Salt draws moisture out of the strand. Rinsing with fresh water before you swim means hair absorbs less salt water, and rinsing afterwards matters more than most people realise.
- Pools. Chlorine is drying and, on lightened hair, can shift the tone. The same pre-swim fresh-water rinse helps, and a little oil through the lengths beforehand gives the strand something else to absorb.
Between washes, and sleeping on curls
Most of what happens to curls happens overnight and between washes, not in the shower.
- Sleep on silk or satin, or in a loose high bun. Cotton creates friction all night.
- Refresh with water rather than more product - a light mist and scrunch revives a clump better than layering.
- Keep hands out of it during the day. Every touch is friction.
- Wear it up on the worst humidity days rather than fighting the air.
My own routine
I have wavy hair, and I live in one of the most humid parts of the country, so this is not theoretical for me.
What changed things was not a product but a pattern: washing less often, using far more conditioner than I was taught to, putting oil on while my hair was still dripping, using a hair treatment once a week and then genuinely leaving it alone to dry. Summers here used to mean a permanent bun. They don't any more though I still have days when the air wins, and I have made peace with those.
It also took a season to settle. If you are changing your routine now, judge it in February, not next week.
Frequently asked questions
Why does my hair frizz in humidity?
Humid air carries more moisture than dry hair does, so water moves into the strand, the cuticle lifts and the curl pattern breaks up unevenly. Well-hydrated hair has less capacity to absorb, so it frizzes less in the same conditions.
Is sulphate-free shampoo better for curly hair?
Generally, yes. Curly and wavy hair is naturally drier because scalp oils travel down a spiral more slowly, so a gentler cleanser that leaves the hair's own lipids in place suits it better than a stripping detergent.
Should I stop washing my hair altogether?
No. Scalp health depends on regular cleansing, and build-up causes its own problems. Washing two to three times a week suits most curly and wavy hair.
How do I know my hair porosity?
The float test gives a rough indication: a clean strand in room-temperature water floats (low porosity), sinks slowly (medium) or sinks quickly (high). Treat it as a starting point rather than a verdict — how your hair behaves after washing tells you more over time.
Does hair oil make frizz worse?
Only when it is used on dry hair, or used too heavily for the hair type. Applied to wet hair in small amounts it helps hold moisture in the strand, which is what reduces frizz.
Can I use these products with the curly girl method?
Yes. Our shampoos are sulphate-free and our conditioners are silicone-free, which covers the two rules the method is built around.
How do I protect my hair at the beach?
Rinse with fresh water before you swim so the hair absorbs less salt water, run a little oil or hair treatment through the lengths, and rinse again afterwards rather than letting salt dry in.
How long before I see a difference?
Some changes - conditioner placement, drying method - show at the next wash. A change of shampoo takes longer; give it a full season before deciding.
Where to start
If you are changing one thing, change how much conditioner you use and where you put it. If you are changing three, add a cooler rinse, a once a week treatment and oil on wet hair.
Everything we make is formulated and produced in Australia, free of sulphates, silicones and synthetic fragrance, and packaged in refillable aluminium rather than plastic. Shop natural shampoo, conditioner and hair oil →
This article is general information about hair care, not medical advice. If you are experiencing scalp irritation, sudden hair loss or a persistent flaking scalp, please speak with your GP or a dermatologist.
