And analysts are concerned that shoppers will likely wait until the last minute to do their holiday buying to get the best deals.
As retailers report their figures on Thursday, the bright spots were Costco Wholesale Corp. and Limited Brands Inc., both of which reported bigger increases than Wall Street analysts expected. Target Corp. posted a small gain that's slightly above Wall Street estimates.
"It was a promotionally driven month," said Jharonne Martis, director of consumer research at Thomson Reuters. "Warm weather hurt sales of fall merchandise. We expect discounting is going to be necessary to drive holiday sales."
According to an early county by Thomson Reuters, six retailers beat estimates, while four missed expectations. One merchant's results met analysts' forecasts.
The figures are based on revenue at stores open at least a year. That's considered a key indicator of a retailer's health because it measures growth at existing locations and excludes new or closed stores.
Experts say October is typically a slow month because it's between the back-to-school season and the start of the holiday shopping period. But shoppers appeared to take more of a breather as they grappled with continued economic uncertainty. Warm weather in many parts of the country also dampened their appetite for fall clothing. That made stores push discounts even more to entice consumers, who are buying even closer to need in the wake of the Great Recession.
Costco said Thursday that its revenue at stores open at least a year climbed 6 percent in October as international results improved in part because of the weaker dollar.
Analysts polled by Thomson Reuters expected a smaller 4.6 percent increase.
Target posted a 1.7 percent gain in October, slightly better than the 1.5 percent estimate from analysts. CEO Gregg Steinhafel said in a statement the results were at the low end of the company's expectations because of softness in the first half of the month.
Steinhafel noted traffic is healthy in stores and the company is seeing essential items selling better than discretionary items.
Limited, the operator of Victoria's Secret, Bath and Body Works and other businesses, reported a 9 percent gain, well above the 6.1 percent forecast. Based on stronger-than-expected results, the company raised its third-quarter earnings forecast.