Fashion-conscious consumers should get used to buying fur coats in the summer and sandals in the winter.
That, at least, is the advice of leading designers, who warn that unpredictable weather patterns caused by climate change are playing havoc with the traditional pattern of spring/summer and autumn/winter collections.
With seasons increasingly out of kilter, customers are no longer guaranteed clothing tailored for specific temperatures.
"The whole fashion industry will have to change", Beppe Modenese, founder of Milan Fashion Week, told The New York Times last week. He said the industry "must adapt to the reality that there is no strong difference between summer and winter any more".
"You can't have everyone showing four times a year to present the same thing. People are not prepared to invest in these clothes that, from one season to the other, use the same fabrics at the same weight," he added.
Modenese was reflecting wider concerns among fashion-world luminaries about the impact of longer summers, particularly on new lines of clothing. Retailers in New York blamed poor autumn sales on a prolonged "Indian summer", with high temperatures suppressing demand for warmer clothing.
Three US fashion giants, Liz Claiborne Inc, Target and Kohl's, have all hired climatologists to help them plan their next collections, and Target is promising to sell swimwear all year round from January.
At Paris Fashion Week, the highly rated young Canadian designer Rad Hourani raised eyebrows following his acclaimed debut collection by declaring that "with global warming, I don't believe in four distinct seasons any more". And the celebrated British designer Katherine Hamnett, known for her overtly political T-shirts and campaigning for ethical consumerism, said that, if the industry did not adapt to climate change, it will not survive. "The entire clothing industry is upside-down right now, and has been for some time," she said. "We have bikinis being sold in January, and fur coats being sold in August. It's bonkers".
Hamnett said that, as weather patterns change, new styles will emerge to satisfy the demands of all-weather clothing. "I think we may see a move toward more layered clothing in the winter, rather than bulk clothing as we seem to favour now. Layers are both more effective and more adaptable: they show the fashion industry being responsive and innovative at the same time.
"The trouble is, climate change is just so unpredictable. It throws conventional patterns out of the window. While the weather fluctuates like it has done recently, I don't think anybody knows how relevant our seasonal collections will be."
Harriet Quick, fashion features director of Vogue UK, said: "Many boutiques are starting to find themselves saddled with heavy winter clothing. I think we'll start to see a move toward what you could call trans-seasonal or all-year clothing."