Stores in the US have reported indifferent revenue gains for September.

The International Council of Shopping Centers-UBS survey of 45 retailers, including Wal-Mart, JC Penney, Federated Department Stores and Kohl's, was up 2.5%, better than the 1.3% gain in August, but well below the average 6% increase of January through May.

The nation's middle and low-income shoppers have kept hands firmly in pockets except to buy essentials such as increasingly expensive food and fuel, while at the same time worrying about their jobs.

The spectacularly tempestuous summer weather in the southern states has also been blamed for poor sales as shoppers and stores battened down the hatches during August and early September.

Data sourced from USA Today Online; additional content by WARC staff