U.S. retailers including Target Corp. (TGT) and Gap Inc. (GPS) posted disappointing July sales Thursday as soaring temperatures and high gasoline prices crimped early back-to-school demand and stoked concerns about consumer spending.

Costco Wholesale Corp., Pacific Sunwear of California Inc. (PSUN) and AnnTaylor Stores Corp. also missed Wall Street forecasts as one of the hottest Julys in 112 years turned shoppers off of early fall fashions.

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Gap warned that second-quarter profit would be lower than expected, but most other chains maintained their earnings forecasts. July marks the end of the fiscal second quarter for most retailers.

Department stores such as J.C. Penney Co. Inc. (JCP) and Nordstrom Inc. were among the winners with better-than-expected growth, but J.C. Penney said it remained cautious about August sales because of a tough economy.

Wall Street has been watching for signs of a spending slowdown as soaring gasoline prices and rising interest rates strain household budgets, particularly among lower-income shoppers.

Industry leader Wal-Mart Stores Inc. (WMT) confirmed that its July sales rose a better-than-expected 2.4 percent at its U.S. stores open at least a year -- also known as same-store sales -- and forecast similar growth for August.

Wal-Mart cut prices on school supplies and clothing to lure cost-conscious shoppers, which may have hurt competitors such as Target Corp., analysts said. Target posted a 3.1 percent same-store sales gain, at the low end of its reduced forecast.

"Our customers continued to prioritize spending on food and consumables and they responded early to price breaks for essential back-to-school supplies," Tom Schoewe, Wal-Mart's chief financial officer, said in a statement.

BACK TO SCHOOL ALREADY?

Overall, analysts are expecting retailers to post a 3.7 percent same-store sales increase for July, according to research firm Retail Metrics. That would be flat with a year earlier, and up from June's 2.8 percent gain.

August is typically the big back-to-school shopping month, but July has become increasingly important because many schools in sunbelt states such as Florida resume in early August.

This July was one of the five hottest in the past 112 years, according to weather forecasters Weather Trends International. The heat wave may have attracted people to air-conditioned malls, but not to early fall fashions.

Pacific Sunwear posted a disappointing 10.6 percent same-store sales decline and cut its profit forecast for the second quarter.

AnnTaylor's same-store sales growth of 5.1 percent was well short of analysts' expectations for a 9.1 percent gain.

Costco (COST), the largest U.S. warehouse club operator, posted a 7 percent same-store sales gain, slightly below Wall Street forecasts for a 7.3 percent gain.

Deutsche Bank analyst Bill Dreher said the gain was even more modest after stripping out sales of pricey gasoline and the benefit of foreign currency.

"On the surface it looks like an OK number," he said. "It's not going to be received that well.

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