After a mostly disappointing spring and summer, August provided a reprieve for several of the most prominent U.S. retailers. Because it marks the beginning of the crucial back-to-school season, the month is an important one. Whether driven by tax rebate checks, or the need for the latest cool clothes for the classroom (or some combination of both), shoppers at most stores returned and helped boost results.

The king daddy of retailers, Wal-Mart (NYSE:WMT), topped its own raised guidance, with a comparable store gain of 6.9%. Fellow discounter Target (NYSE:TGT) also had an impressive showing, with a gain of 5.7%. Warehouse club giant Costco (NASDAQ:COST) beat them both with a 9% increase.

Results among the specialty retailers were, as usual, more mixed. Two teen retailers that have consistently performed well this year, Hott Topic (NASDAQ:HOTT) and Pacific Sunwear (NASDAQ:PSUN), kept the party going with comps increases of 11.8% and 15.6% respectively. Another teen fave, accessories chain Claire's (NYSE:CLE), posted a gain of 8%.

Not all retailers catering to the MTV set had it so easy, though. Abercrombie & Fitch (NYSE:ANF) reported another disappointing month, with comps down 11%. Rival American Eagle (NASDAQ:AEOS) hardly fared any better with a drop of 10.4%. Wet Seal (NASDAQ:WTSLA) rounds out the triad of bummers with its comps decline of 10.7%.

Gap's (NYSE:GPS) comp sales grew by 4%, which was below expectations for the rebounding retailer, while Ann Taylor (NYSE:ANN), on the other hand, had a good month with comps up 8.2%. Chico's FAS (NYSE:CHS), which reported its August sales results yesterday, again posted outstanding numbers, with comps up 19.4%.

The back-to-school story isn't quite over yet. With these retailers now in the second month of their third quarters, we'll have to wait and see if September proves to be as good as August before we can say how the season is shaping up.

LouAnn Lofton owns shares of Gap and Abercrombie & Fitch.