A cardigan might not sound like much of a new season must-have. A killer pair of heels? Yes. The latest blinged-up handbag? Of course. But an I-absolutely-must-have-that woolly jumper?

Believe it or not, it’s all about the It knit this season: jumpers and cardigans stitched and purled into artful creations, oversized, armless or with in-built scarves, made from lamé threads, spliced with crochet sleeves and embellished with sequins and beads to within an inch of their yarn count. And with the wind and rain ravaging what’s left of our summer, there is no better time to dive in.

We can thank Miuccia Prada for this high-fashion reinvention; she sent an intricately beaded £3,000 cardigan (slung over another knitted jumper and paired with a knitted skirt) down her autumn/winter catwalk. Vogue is calling it the “trophy purchase of the season”. When the glossies are championing a cardigan over a Saint Laurent stiletto or Louis Vuitton’s latest Damier print phone case, you know that something is afoot.

£975, Gucci at net-a-porter.com

Hardcore fashion fans will already recognise Gucci’s saccharine knitted sweaters emblazoned with motifs including, but not limited to, diamonds, lions, lovehearts, butterflies and a pair of Dutch rabbits, which have been worn by the upper echelons of the A-list, from Beyoncé to Mirka Federer. At Glastonbury, Chinti & Parker’s star and cherry-print cashmere knits were worn like uniform by Margot Robbie, Cara Delevingne and their gang, while at this month’s Copenhagen Fashion Week, Ganni’s buttercup Faucher pullover was the surprise must-have among fashion editors.

Even how you style your knit when you’re not wearing it has become a source of one-upmanship among the fashion pack lately. Anna Wintour goes for the traditional around-the-neck shawl; Alexa Chung hangs hers perilously from one shoulder; Olivia Palermo ties hers diagonally across her chest. Such is fashion’s dedication to off-kilter jumper-draping that Michael Kors last week debuted the “schmoo” — a knitted creation that can be worn round the waist or neck “like a security blanket”, according to the designer.

Until recently, statement knitwear was a contradiction in terms. Apart from a few outliers — David Bowie’s knitted catsuit phase in the early 1970s, and the fad for batwing sleeves in the 1980s — knitwear has rarely made any statement at all. Instead, it quietly gets on with the job in hand: keeping you warm. Pairing something woolly with fine jewellery and expensive leather skirts for evening events or fashion shows is a surprising new development, but a welcome one.

“Knitwear isn’t consigned to a particular time or place any more,” says Cassie Holland, the brains behind Hades, a London-based knitwear label that counts Chung among its fans. “I wear mine to work and in the evening to dinner and drinks. The colour you get from wool is so rich, which is great for occasions, and I like the fun a bold design brings to an outfit.”

Her designs, which are scrawled with bon mots, have struck a chord with shoppers; the label’s past two collections sold out within 24 hours, although the “Bonjour Tristesse” jumper in sugar pink and blue has been restocked (£160, www.hades-shop.co.uk).

This is brilliant news for those of us who prioritise comfort as we blearily assemble our outfits in the morning. A cosy stockinette stitch knit with a razzed-up neckline or a splashy print is something of a sartorial top trump — a garment that you can throw on (without ironing) in the morning, adding pep to an otherwise pedestrian pair of jeans or an A-line skirt. And it’s comfortable, not always a given when it comes to the pieces that inspire fanaticism in the fashion world.

Where you shop for your It knit depends on how look-at-me you like your clothes to be. Tara Jarmon’s knitwear is a good place to start for those who prefer a little flourish, rather than a loud shout. The grey Adornet jumper features a scattering of gems around the neckline (£330), while a bottle-green cardigan is fastened with jewelled flowers in place of buttons (£255, both tarajarmon.com).

On the high street Zara has a handful of embellished knits, including a Prada-esque bejewelled cardigan for £49.99 (zara.com). Meanwhile, Chinti & Parker offers cashmere sweaters that feature panels of eye-popping pink and orange on the back, but easy-to-wear grey or black at the front (£275, chintiandparker.com).

Metallic knits might sound scary, but they can actually be rather discreet — and they reflect on skin to give it a flattering warmth. Missoni’s midnight-blue lurex sweater is certainly not humdrum (neither is the £450 price tag, net-a-porter.com) and would look posh enough for an evening event tucked into smart denim or an on-trend asymmetric skirt.

Mint Velvet’s rose gold jumper would also do the trick (£89, mintvelvet.co.uk). If you’re game for wearing slogans, Bella Freud’s “Horses”, knitted in wonky bubble writing, is the designer’s latest must-have (it has already been worn by Karl Lagerfeld’s right-hand woman, Amanda Harlech; £290, bellafreud.com), or try Hush’s “Love” jumper for a fraction of the price (£85, hush-uk.com).

Red is the new season’s hottest shade, as recently demonstrated by Victoria Beckham, who stepped out in New York wearing a knitted vermilion jumper and matching knitted skirt. I’ve got my eyes on Topshop’s crimson roll-neck (£39, topshop.com), which I’d wear, à la Beckham, with Uterque’s red midi skirt (£115, uterque.com).

A rainbow of horizontal stripes is another way to add colour and looks very Gucci, but if you can’t afford the real thing, try John Lewis’s new collection of bright, striped 100 per cent cashmeres (£89, johnlewis.com), which might yet be the sunniest thing to come out of August. Pull on an It knit now and, given the weather forecast, you won’t take it off until spring.