And what you need to change.
Temperature, humidity, UV exposure, central heating, wind, swimming and even how much time you spend outside can all affect how your hair feels and behaves.
That's why the routine that gives you brilliant results in July might have you pulling your hair out by December.
You don't necessarily need completely different products for every season.
The trick is understanding what your hair is dealing with and adjusting your routine accordingly.
Summer can be a mixed bag for wavy hair.
Higher humidity can encourage some people's natural pattern, but it can also cause frizz as hair interacts with moisture in the air. Then you've got sunshine, chlorine and salt water potentially contributing to dryness and damage.
During summer, focus on protection, cleansing and lightweight hold.
If you're swimming regularly, rinse your hair with fresh water before and afterwards, rather than leaving chlorine or salt sitting on your strands.
You may also find you need to clarify more frequently to remove stubborn build-up from styling products, sweat and everything else summer throws at your hair.
Styling-wise, resist the temptation to fight humidity by applying increasingly heavy products. Wavy hair can quickly become weighed down.
Instead, use lightweight products that provide definition and hold while allowing your waves to move naturally.
And don't forget UV exposure. Just as prolonged sunshine affects your skin, it can affect your hair too, contributing to dryness, colour changes and structural damage. Hats and physical protection are essential when you’re spending long periods outside.
Winter brings a completely different set of problems.
Cold outdoor air combined with heated indoor environments can leave your hair feeling noticeably drier. Wind, scarves, coats and woolly hats can also mean more friction and tangling.
If your waves start feeling rough, straw-like or unusually frizzy, you may need to increase the moisture in your routine.
That doesn't mean covering your hair in the richest products you can find.
Waves are still waves.
Too much heavy conditioning can leave them limp and unable to hold their shape.
Instead, make small adjustments. Deep condition a little more often when your hair feels dry, pay extra attention to your ends, and make sure you're not unnecessarily over-cleansing.
Winter is also a good time to look at mechanical damage. Constantly pulling your hair out from underneath coats, rubbing against scarves, or aggressively brushing winter tangles can all put additional stress on fragile strands.
Be gentle when detangling and consider protecting your hair overnight with a satin or silk pillowcase or bonnet.
Not everything needs to change.
Whatever the season, the foundations of a good wavy hair routine remain pretty consistent:
- Cleanse your scalp when it needs it
- Condition your lengths and ends
- Detangle gently
- Style while your hair is wet
- Use lightweight products rather than overwhelming your waves
- Minimise unnecessary heat and friction
- Clarify when you notice build-up
- Pay attention to what your hair is telling you
Think of your seasonal routine as adjusting the dials rather than starting from scratch.
Summer may require more protection and cleansing.
Winter may require more moisture and protection from friction.
Sometimes changing your routine isn't just about getting a better wash day.
It's about dealing with what the previous season left behind.
After summer, your hair may be feeling the effects of weeks of sun, swimming, heat and holidays. After winter, it may be dry and fragile from months of central heating, cold weather and friction.
Signs of accumulated damage can include roughness, split ends, increased tangling, snapping and hair that generally feels weaker than it used to.
That's when a more targeted treatment routine can be useful.
The Merwave Repair & Restore Kit is designed for hair that needs more than its usual conditioning routine, combining treatments to help strengthen, moisturise and protect damaged hair.
It's particularly useful as a seasonal reset – whether you're repairing your waves after a summer of sun and swimming or giving dry winter hair some extra attention.
There isn't a date when you suddenly need to switch from your "summer routine" to your "winter routine".
Your hair will tell you.
If it becomes dry, increase moisture. If it's getting heavy, clarify. If humidity is destroying your definition, focus on hold. If your ends are becoming rough and fragile, give them some extra protection.
The best wavy hair routine isn't one you follow exactly for 12 months.
It's one that changes when your waves do.
