A view from Sue Unerman

Rain, rain, go away

The last couple of weeks of July felt like a very British summer - especially the penultimate Friday, when an ark would have been appropriate...

The unseasonable – or perhaps typically unpredictable – weather reminded me of a story from a creative agency chief executive about a new-business pitch that meant she made an ad for a retailer purely on payment by results. For every item the brand sold over and above the sales of the previous year's equivalent product, the agency would take a share. To quote her: "The ad was for winter coats… And it was the warmest autumn since records began. Not only didn't we get any extra sales, we ended up practically owing them money." They say "time is money". Well, so is the weather.

The new Weathernomics report from The Weather Channel describes the effect British weather has on retail sales with great precision. Of course, interest in and discussion of the weather remains a defining characteristic of the British. There's clearly a lot less to talk about in Florida in June or Helsinki in January. Our weather is less predictable and therefore can lead to a swing in sales for a brand that can be hard to cater for or to explain to shareholders. Movies can be made or broken by a sunny or rainy bank holiday opening weekend.

Sixty per cent of shoppers change their shopping behaviour depending on whether it's raining or sunny. A third don't go to the shops in the rain; just one in eight claim to shop more but switch to a shopping centre instead. Of course, more rain means more shopping online, and sophisticated online retailers have sites designed to leverage the weather.

The UK must be one of the most difficult territories to plan for the weather accurately. With global clients based outside the UK, it's just another stress point for a weather-reliant brand's marketing team. The weather is getting less predictable and more extreme, according to many reports. Yet it's not only extreme weather that makes a difference: this report says that a week of sleet can affect sales more than a day or two of snow.

In an ideal world, you would keep stock of and arrange promotions for products that fitted the weather and turn on promotions and advertising regionally to suit the best prospects for sales, such as barbecue equipment or raincoats. Weathernomics highlights that weather can affect consumer purchase in other ways too, such as timing: mild autumns mean delaying buying that winter coat; early spring precipitates the trip to the garden centre.

The solution to all this lies in more agile ways of working, contingency plans, real-time course correction with immediate media, copy and regional flexibility. It is a lot simpler to arrange copy substitution now online or via Sky AdSmart than it used to be, and all kinds of brands and retailers will benefit from this flexibility.

I'm off for a week at the English seaside, so expect rain this month.

Sue Unerman is the chief strategy officer at MediaCom