May same-store sales data for retailers is out today, and despite the month's reputation for flowers and pleasant weather, the numbers looked anything but rosy. Investors' outlook for retail stocks may be exuberantly sunny, but this industry remains battered by economic storm clouds.

 Let's take a look at some of the highlights:

Company

CAPS Rating (out of 5)

May Comps

May Net Sales

Target

***

(6.1%)

(2.3%)

Costco (NASDAQ:COST)

****

(7%)

(5%)

Gap (NYSE:GPS)

*

(6%)

(5%)

Abercrombie & Fitch (NYSE:ANF)

**

(28%)

(22%)

The Buckle (NYSE:BKE)

**

13.4%

19.2%

Aeropostale (NYSE:ARO)

**

19%

30%

Hot Topic (NASDAQ:HOTT)

*

(6.4%)

(2.9%)

All data from CAPS and Yahoo! Finance.

The only people who should be surprised at these figures may be those who thought the economy showed stronger signs of near-term recovery. I didn't really buy all the "green shoots" talk, figuring we might just be in the eye of the storm. These figures seem to back up that idea.

Even consumers unburdened by unemployment or debt clearly remain reluctant to spend money. Anyone expecting a quick recovery in retail will have to wait a bit longer. And investors who have been neglecting the firms' operational strength, balance sheets, or competitive landscape may see their portfolios get killed by retail stocks they supposed were "cheap."

I found no surprises among these comps -- the companies to which they belong have been flailing for months. Abercrombie & Fitch's comps are breathtakingly ugly. Gap's, like the company's fashion offerings, are sadly nothing new. The Buckle and Aeropostale remain retail outliers, while Hot Topic appears to be running out of steam.

Another interesting piece of the May sales data is what's missing: Wal-Mart's (NYSE:WMT) monthly numbers. The retailing behemoth recently decided to stop reporting monthly same-store sales. Given the widespread perception that Wal-Mart serves as a barometer for the entire economy, that move is both interesting and disappointing.

Steer clear of retail wrecks
As always, one month's same-store sales are no reason to buy or sell a stock; it's more important to watch for trends over time. Like I said, stocks such as Gap suffered from ugly same-store sales even before the economy took a turn. And right now, most retail companies remain at the mercy of the larger macroeconomic picture.

Preliminary data from Goldman Sachs and the International Council of Shopping Centers indicate that same-store sales in May fell 4.6% overall -- worse than the 3% decrease observers expected. Headwinds continue to buffet the retail sector, and the wrecking balls may hit malls in the future.

As consumers continue to struggle, many retailers face their own challenges to remain afloat and competitive. Exercise caution when shopping for these volatile stocks, and remember to keep an eye out for the strongest companies in the sector before investing. In that regard, same-store sales can be a great gauge.

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Costco Wholesale and Wal-Mart are Motley Fool Inside Value picks. Costco is also a Stock Advisor selection, and the Fool owns shares of it. Try any of our Foolish newsletter services free for 30 days.

Alyce Lomax does not own shares of any of the companies mentioned. The Fool has a disclosure policy.