Sienna Miller just traded in her signature waves for a heatwave-proof bun - and it's so easy to try
Effortlessly undone, Sienna Miller's updo is a stylish, practical solution to the rising temperatures
If you're like us, you'll be doing anything to prevent your hair from sitting at the nape of your neck during the heatwave.
In temperatures like this, strands of hair sitting against clammy skin can lead to sensory overload – not to mention, any sweatiness can leave your tresses oily, even if they've just been washed.
So, we've been scouring the list of 2026 hair trends for low-effort hair up styles that will not only keep our hair out of the way, but still look stylish. Thankfully, Sienna Miller just stepped out debuting an all too relatable, undone ballerina bun that is perfectly apt for warm weather – and it's so easy to recreate.
RRP: £29
A known favourite of Sienna Miller's for achieving her tousled texture, this lightweight texturising spray encourages texture and hold at the roots and throughout lengths, without weighing heavily on the strands. A spritz of this either before or after styling gives the hair a natural-looking, undone effect.
RRP: £5.99 for 20
You'll want to invest in hair ties that will keep your updo in place all day long. Forget snagging, pulling or styling that falls out within hours, these soft and stretchy nylon ties are designed to securely and comfortably keep your hair looking polished. Their flexible nature also allows hair to glide smoothly through, without damaging the tresses or causing any breakage.
RRP: £27
As temperatures rise, you might be searching for a way to weather-proof your strands. That's where Color Wow's Dream Coat Supernatural Spray comes into play. This nifty anti-frizz formula boasts humidity-blocking technology that prevents the moisture in the air from ruining your hairstyle. The texture is so lightweight that it's almost like an invisible veil over your hair that lasts for three to four shampoos – and that you can't even detect.
Unlike traditional red carpet hairstyles, Miller's look takes an 'undone' approach, rather than being perfectly preened and locked in place. Instead, the look embraces flyaways and loose strands, yet it remains totally chic.
The elevated yet fuss-free style says 'I just quickly chucked my hair into a bun to get it out of my face', which only adds to its relatability – especially in this heat.
The great thing about this hairstyle is that it lends itself to a number of occasions, whether that be sweeping your hair up to run errands, a special dressy event, or a star-studded red carpet in Sienna Miller's case.
If your hair is shorter than Sienna's, worry not, as the low height of the ballerina bun allows you to achieve the look on shorter strands too. Simply pull your locks back into a ponytail at your desired height, before twisting said ponytail and wrapping it around the hair tie and securing it with grips. If shorter bits fall out, simply pin those up individually, then use a pin-tail comb, or your fingers, to pull out random strands of hair for the effortless effect.
