Dr Martens, the bootmaker, said its full-year results now depend on the Christmas trading period after a hot summer hit boot sales and pushed it to a bigger first-half loss.
The FTSE 250 company said there was a wide range of possible outcomes for both revenue and profit this year.
Analysts currently forecast revenue of £777 million and an adjusted pre-tax profit of £65.7 million.
Revenue fell around 15% in October, the same pace of decline as in the second quarter.
Chief executive Ije Nwokorie said: "Trading in the key weeks ahead will be crucial to determining our full year outturn."
Boots slump
Revenue fell 9% at constant currency to £290.4 million in the six months to 27 September.
The adjusted pre-tax loss widened to £13.7 million from £9.4 million a year earlier.
Boot sales fell 20% and now account for 44% of revenue, down from 49%.
Shoe sales rose 1% and sandals grew 5%, helped by the hot weather.
Sales to consumers through its own shops and websites fell 13%, partly because its new online store lost traffic after launching in the US and Europe over the summer.
Sales to wholesale customers fell 5%.
UK sales slide
UK revenue dropped 21% in what the company called a challenging and highly promotional market.
US sales fell 5%, while weak trading in France, Italy and Spain offset strong growth in South Korea.
Gross margin held steady at 65.3%, and the company cut operating costs outside marketing by £13 million.
Marketing spending rose by £3 million ahead of the launch of its new brand campaign, With Bouncing Soles, in late September.
Net debt, including leases, rose to £310.8 million from £302.3 million a year earlier.
The interim dividend is unchanged at 0.85p.
