Bonmarche has issued a profit warning after reporting "extremely poor" sales of its autumn range in September because of the recent hot weather, which has seen Sptember temperatures three degrees centigrade above average.
Helen Connolly replaced chief executive Beth Butterwick this summer.
Bonmarche said: "It is appropriate to lower the profit expectation for the second half of the year.
"The board's view is the company's full year profit before tax is likely to fall within a range between £5m & £7m."
Bonmarche also experienced difficult trading conditions in July and August.
It added: "We approach the beginning of the second half of the year facing considerable uncertainty as to market conditions.
"The hot September has prevented us from gaining a representative measure of the strength of the autumn ranges and our perception is that the clothing market generally has become more challenging.
"The board's view is that in the light of September's result, and its generally less optimistic view of market conditions, it is appropriate to lower the profit expectation for the second half of the year."
However, the company reported that its financial position "remains strong" and it expects to end the half year with a net cash balance of around £9m.
Bonmarche, established in 1982, describes itself as "one of the UK's largest women's value retailers" and has 312 stores around the UK, including a presence in garden centres such as Wyevale and Tong.