NEW YORK (CNN/Money) - Retail sales in the United States were sluggish in May, as bad weather kept consumers -- already wary because of rising unemployment, falling stock prices, threats of terror attacks and more -- away from stores.

While department-store chains such as Sears and Federated suffered the most, as they have for the past several months, the weather also caused disappointing sales at some discount retailers, such as Target Corp., trying to sell lines of summer clothing.

"There's no question that consumer momentum is slowing," retail analyst Kevin Tawes of Independence Investments, a unit of John Hancock Financial Services, told Reuters. "Consumers have lost the tailwind that had pushed them forward, and we can't ask or expect more of them in the months ahead."

Sears, Roebuck and Co. (S: Research, Estimates), the No. 4 U.S. retailer, said sales in stores open for at least a year -- a key measure of retail performance known as "same-store" sales -- fell 4.4 percent in May.

Federated Department Stores Inc. (FD: Research, Estimates) posted a 3.4 percent decline in May same-store sales The operator of Macy's, Bloomingdale's and other chains blamed much of the decline on cooler-than-expected weather that hurt sales of seasonable items.

J.C. Penney Co. (JCP: Research, Estimates) reported a 5.1 percent drop in May sales Thursday at stores open at least a year, hurt by stronger-than-expected first quarter sales that depleted inventory levels.

Despite the decline, Penney reiterated full-year earnings guidance of 90 cents to $1 a share.

The Plano, Texas-based retailer also said same-store sales increased 6.7 percent at its Eckerd drugstore division from a year earlier, in line with company expectations. But catalog sales fell 19.1 percent, below expectations.

May Department Stores Co. (MAY: Research, Estimates), which operates Lord & Taylor's, Filene's and other chains, reported a 7.6-percent plunge in same-store sales.

And Dillard's Inc. (DDS: Research, Estimates) reported a 1 percent decline in its same-store sales. The Little Rock, Ark.-based department store chain also said sales were lower for the year-to-date period. The company's shares rose 38 cents to $30.16 Wednesday.

Meanwhile, discount operator Target Corp. (TGT: Research, Estimates) posted a 2.6 percent increase in May same-store sales, but the company said that figure was "modestly below plan." Among discount chains, Target suffered more because they carry more clothing than some of the other discount lines, some analysts said.

TJX Cos. Inc. (TJX: Research, Estimates), operator of off-price chains T.J. Maxx, Marshall's and other stores, said May same-store sales increased 3 percent from a year earlier. TJX shares added 45 cents to $21 Wednesday.

Wal-Mart Stores Inc. (WMT: Research, Estimates), the world's biggest retailer, reported a 6.2 percent increase in its May same-store sales Wednesday.

Retail sales are a key early gauge of consumer spending, which is closely watched by economists and policy makers because it makes up about two-thirds of the U.S. economy.

To keep consumers spending despite a recession, rising unemployment and other woes, the Federal Reserve cut its target for short-term interest rates 11 times in 2001. Fed policy makers have kept their key interest rate at a 40-year low and are expected to do so until the labor market begins to stabilize.