Florette has launched what is believed to be the first

TV advertising campaign to run only when the weather is warm enough.

In a move set to revolutionise food marketing, the prepared salad specialist is using 'thermal advertising' to dictate when its World of Florette ad airs on ITV, Channel 4 and Five.

The ads, which kicked off last week, will run only when the temperature tops 20C in the north and 22C in the south of the UK. Each day the temperature will be checked against ITV Weather Centre data to establish if the ads can run.

Florette agreed the deal following last year's poor summer to allow it to advertise to consumers when they were in a 'warm weather mindset'.

"This year, we wanted a TV advertising campaign that was more flexible, to enable us to advertise when the weather is warm and better prompt the consumer into purchasing salad," said Florette marketing manager Elaine Smith.

Thermal advertising would also allow Florette to save money on its advertising during cooler periods, she said, adding that any money saved would be rolled over to its winter advertising budget.

The company was also liaising with retailers about how to handle any peaks or troughs in demand prompted by the campaign.

The thermal package will run for 10 weeks, and is being linked to high-profile shows such as Coronation Street, Emmerdale and Ramsay's Kitchen Nightmares.

Last year Florette's sales, along with those of the prepared salads category as a whole, suffered as a result of the poor summer.

The company has already experienced a sales uplift this summer, with Florette value sales for the four weeks to 14 June up 28% to £4.3m compared with the same period last year. The £3m World of Florette TV ad, which was created by Florette with the Hooper Galton Agency and advertising service The Media Shop, initially launched in April.

"Similar things have been tried in radio but this may well be a first for television," said John Alligan, director of The Media Shop.