Rivers and reservoirs haven’t been the only things impacted by the series of heatwaves which have marked the summer of 2026 as likely to be the hottest on record. It will also have a huge impact on fashion merchandisers and their planning for seasonal garments.
Traditionally, they have built seasonal assortments based around predictable seasons - spring, summer (SS), autumn and winter (AW). Seasonal calendars are planned 12 months ahead, including assortment depth (how many trousers, tops, swimwear etc), colour palette and size distributions. Fabrics need booking, minimum order quantity (MOQ) needs agreeing and visual merchandising cycles need planning months ahead.
All geared to maximising our ability to purchase our flip flops in May ready for the annual pilgrimage to Paphos, and our raincoats in August when the AW collections have traditionally been launched, ready for, well rain. And in amongst all this, it is vital to minimise markdowns.
It’s a well-oiled machine which has operated in this way for decades. Until now.
Because, if the evidence wasn’t there already, the summer of 2026 is proving that predictable climate - something which the traditional merchandising model relies upon - no longer exists. The fashion calendar as we know it is being eroded and fashion retailers will need to adapt to a new normal.
2026 Heatwaves
The heatwaves experienced with temperatures exceeding 40°C across parts of Southern and Western Europe so far this summer have disrupted travel, reduced retail footfall, and shifted consumer behaviour. But more importantly, they have exposed the fragility of fashion’s seasonal model.
More especially, they have exposed a structural weakness within an industry whose planning cycles still reflect twentieth-century climate patterns rather than the climate realities of the twenty-first-century.
The significance of this shift became particularly clear when H&M announced the redesign of its autumn collections using lighter fabrics and adjusting its merchandising calendar to account for longer, hotter summers. And in doing so, ‘transitional’ merchandising was born.
The implications of all this for retailers are many and varied; for example, climate volatility will inevitably increase commercial risk. As summer extends further into September and October, a time when winter collections would traditionally be launched, the decision to continue to give space to summer ranges will come with its own commercial considerations.
Earlier, I hinted at the challenge facing Europe, but even within the UK, the regional differences between the south and further north and Scotland can prove to be significant. We could be facing summer ranging in Southampton, while in Aberdeen, a winter collection might be needed. It was always the case, however, it’s just that now, the geographical variations are far more acute.
This will lead to even more dynamic regional merchandising - one ‘size’ most certainly won’t fit all.
Buying and merchandising will no longer be able to rely on historical sales data. Climate is influencing virtually every aspect of a retail business: inventory allocation, sourcing geography, logistics planning, energy management, retail operations, workforce productivity, and capital investment.
Climate intelligence and AI-led demand forecasting will need to become deeply embedded within the business, and sufficiently sophisticated in order to cater for the complexities of climate driven consumer behaviour.
Having stock in the right place, at the right time, has always been critical. Successfully aligning product, stock, and timing with the climate consumers actually experience - as opposed to the calendar - will characterise those who succeed.