Can retailers do well this holiday season, with so many concerns weighing on consumers? November's comps data held a wintry mix to contemplate.

According to The Wall Street Journal, Thomson Financial's data shows that across the industry, same-store sales increased 4%, which did outpace the 3.3% increase analysts expected. However, it's not all good news for retailers because more than half of them actually missed expectations. Meanwhile, the 4% increase was impressive against the 1.6% increase in October; a 1.4% increase in September marked a three-year low.

It's worse than that, though. Some retailers' November comps really weren't so hot despite appearances, and the investors should fasten their seatbelts because December will likely be a bumpy ride.

Bright or blight?
There are more reasons why investors should have avoided any rash decisions on yesterday's comps data. Foolish colleague Seth Jayson explains that many retailers didn't give the full picture of their comps, which were thrown off this year by a calendar shift that put an extra week of post-Thanksgiving sales into November. 

Target (NYSE:TGT) is a good example. Although it reported an impressive 17% increase in total sales, its comps missed its own forecast of a 2% to 4% increase, rising only 1.1% after adjusting for those extra shopping days in November. Target said that while its sales met expectations during its two-day Thanksgiving event, sales softened up during the final week of November. Target also cautioned investors that December is not looking too hot.

Had Target not adjusted its comps to reflect the calendar shift, it would have reported a 10.8% comps increase. Night and day, isn't it? Target should be given kudos for painting the real picture.

Macy's (NYSE:M) sounded like it had a merry November with its 13.4% comps increase, but in the company's press release, CEO Terry Lundgren did admit that the number benefited from that extra week this year as opposed to last year. Lundgren also said that, obviously, that calendar shift will work out to a decrease in comps for December.   

A dismal December ahead?  
People seemed to respond warmly to Wal-Mart's (NYSE:WMT) 1.5% increase in comps (not including fuel sales). It dubbed its Black Friday sales "solid." However, Wal-Mart didn't adjust for the extra week, although at the bottom of the press release it did disclose the fact that there was a calendar shift.

Gap (NYSE:GPS) reported flat comps, which surprised everybody because it was better than analysts expected -- but let's not get ahead of ourselves on the optimism, folks. Read further down in its press announcement and it does adjust for the calendar shift, revealing its comps fell 4% on that basis. Aeropostale's (NYSE:ARO) 6.6% increase in comps were also on a pro forma basis.   

Abercrombie & Fitch's (NYSE:ANF) press release really piled on the mixed messages. Although it boasted of its 25% increase in net sales for the four weeks ending Dec. 1, 2007, versus the period ended Nov. 25, 2006, it used a different four weeks for its comps. Its November comps increased 2% for the four weeks ended Dec. 1, 2007, versus the four weeks ended Dec. 2, 2006. Get your story straight, people.

A chilly Christmas?
It does sound as if December might be rough on retailers. When it's time to report December comps, they won't have that extra week of holiday shopping madness. In addition, given the problems pressuring the American consumer, shoppers will be much more careful this year than last; many news sources have reported on a big drop-off in shopping already. Some consumers may be so deep in financial trouble they'll have little choice but to tighten their purse strings.

I admit I'm nervous about the coming months. It's why I feel it's best to be cautious with retail stocks, avoiding the ones with high price tags or that have struggled with turnarounds and choosing instead well-managed companies with strong brands and reasonable stock prices.

I don't think there's any reason to throw out all retailers, but investors should be careful and critical. The truth behind November's comps numbers show it's a good time to tread carefully.  

Related Retail Foolishness:

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