The rises and falls in the length of skirts are said to be a good way of forecasting what the weather will be like three days in advance, based on research at eBay.
Analysts at the company said the length ugg boots clearance of skirts sold on the website becomes shorter several days before the weather changes for the better, and lengthens when colder conditions are due.
On occasions, the trend is said to have predicted a shift in the weather before any advice has been issued by the Met Office using more traditional meteorological methods.
Demand for skirts on the internet auction site reportedly rose by 200 per cent a week before the recent hot weather began, several days before forecasters had ugg boots clearance announced it.
Ruth Szyszkowski, of eBay, told the Daily Mail: "We're calling it mini skirt meteorology. If you want to know what the weather is going to be like in three days, just take a look at hemlines."
:: Conditions during the remainder of the Bank Holiday weekend are set to improve, forecasters at the Met Office said.
The warmer weather that arrived in much of the country on Sunday is set to remain for at least the first half of the week, with temperatures reaching up to 24C (75F) on ugg boots clearance
Wednesday.