Warmer weather in September could cost non-food retailers £80m per week, a new report has warned.

The British Retail Consortium’s Weather to Shop? study, based on Met Office analysis, suggests the impact of the climate on consumer spending is strongest between mid-August and early October, when warmer weather delays the purchase of autumn-winter ranges.

sunny weather boosts footfall

Warmer weather delays the purchase of autumn-winter ranges

For each degree warmer it is than the previous year, growth in sales is reduced by 1.1% – equivalent to around £40m per week – the analysis found.

Temperatures this summer have been on average 2C warmer than in 2017. If that trend continues, the BRC warns, non-food retailers will see £80m per week wiped off their till roll.

The forecast will serve as another blow to high street businesses including House of Fraser, Debenhams and Marks & Spencer, which are already grappling to increase sales against a turbulent high street backdrop.

The BRC said warmer weather during autumn could have “a lasting effect” on individual retailers, with weaker sales at the start of the season causing a spike in the amount of stock being held and therefore driving deeper discounting.

However, the BRC insists that any sales lost to unseasonable weather are “largely recovered once temperatures normalise” and argued that temperature changes could not be blamed for the downward trend in non-food sales growth since 2014.

The BRC’s head of insight and analytics, Rachel Lund, said: “While few in the retail industry would deny that the weather impacts how we shop, the fact that this study reveals that its impact can be large and changeable only serves to highlight some of the complexity retailers have to navigate in serving consumers.

“The ability to understand and respond to unseasonable weather is clearly crucial for retailers wanting to thrive in today’s extremely competitive retail market.”

Met Office weather analytics manager Malcolm Lee added: “Analyses of this type can’t predict ‘boom or bust’ for the high street based on our weather forecasts, but can offer business insight into how weather has impacted on sales in previous years.

“This research shows that for certain product lines at certain times of year, sales growth is strongly influenced by the weather.

“However, there is much less evidence that total sales are impacted over the season as a whole; it is the profile of the spend in the season (such as early or late season shopping) that the weather impacts most strongly.”