It’s sunny. It’s rainy. It’s unseasonably warm at 9am, then biblical at lunch. It’s this time of year that inspired the fashion world to create the word ‘transitional’.

So in addition to your brolly and a stiff upper lip, the most critical part of your armoury this month should be a versatile jacket – lightweight, waterproof and able to take you from rain to shine and back again. The trenchcoat is one such hero piece, invented in Britain because we know a thing or two about inclement weather.

Seek out classic silhouettes in a gabardine finish – chic and waterproof. Burberry is your go-to brand, but Mango does a great high-street version (see below).

Also key are sporty coats that look artfully dishevelled (see Marks & Spencers’ genius style) and can be stuffed in a bag when it’s sunny. Details like drawstring fastenings and leather panels add style points while still being practical. Come on weather, do your worst.

The 5 best transitional coats