Updated from 9:47 a.m. EDT

U.S. retail chains reported another soft month of sales on Thursday as bad weather and high gas prices kept shoppers at bay in June.

The results fueled Wall Street's concerns about consumer spending, but analysts were quick to point out that retailers were facing their toughest monthly comparisons in over a year.

Ken Perkins, president of RetailMetrics LLC, said his firm's index tracking over 60 major retailers showed a 2.8% overall increase in same-store sales for the month, missing its previous forecast that called for a 3% gain.

Perkins called the results a "mixed bag," noting that, excluding Wal-Mart's ( WMT) lackluster performance, the index rose by a respectable 4.4%. Last June, the index posted a gain of 5.4%, so many retailers faced high hurdles this time around. Meanwhile, heavy rains and flooding across several regions of the country made for a tough business climate.

"As for the broader picture, it does look like the economy is starting to slow here a bit thanks to high oil prices and the slowing housing market, but as the job market continues to show strength, it's hard to say that those factors are affecting these sales figures here," says Perkins. "We'll be watching July numbers very closely. This is the third soft month in the last five, so continued softness would really show that the consumer is starting to feel some fatigue."

Wal-Mart, the world's largest retailer, said its same-store sales rose 1.2%, matching a forecast provided last weekend. Wal-Mart pegged second-quarter earnings at 70 cents to 74 cents a share; analysts were calling for 73 cents a share.

Wal-Mart's chief competitor, Target ( TGT), beat expectations with a 4.8% jump in June comps. Wall Street's estimate called for a 4.3% gain, according to Thomson First Call. The retailer said it expects to meet or surpass analysts' estimate for second-quarter earnings of 69 cents a share. Target also forecast that its July same-store sales will increase in a range between 4% and 6%.

To watch Nat Worden's discussion with Farnoosh Torabi about same-store sales, please click here .

Elsewhere in discount retailing, B.J.'s ( BJ) said last month's same-store sales fell 0.1%, badly missing the expected increase of 2.4%, and the wholesale chain cut its second-quarter earnings guidance to 37 cents to 40 cents a share from 43 cents to 47 cents a share.

At Costco ( COST), same-store sales rose 6% from last year, missing estimates for growth of about 7%. Overall sales rose 10% to $5.74 billion. Chico's ( CHS) said June same-store sales rose 5.1% from a year ago, while total sales surged 17% to $153.3 million. Analysts had expected same-store sales growth of 5.8% in the quarter.

Specialty-apparel giant Gap ( GPS) said June comps tumbled 6%, about a percentage point more than expected. The decline was paced by Gap International, where same-store sales fell 14%. Gap's close rival, Limited, said June comps gained 3%, while total sales rose 5% to $1.08 billion. Analysts were forecasting same-store sales growth of 5.1% last month.

Federated Department Stores ( FD) posted a 1.7% rise in June same-store sales, missing estimates for a 2.8% gain. The company put second-quarter earnings at 39 cents to 44 cents a share, whereas analysts were predicting 44 cents.

Most department store chains showed unexpected strength in the month. J.C. Penney ( JCP) reported a 4.3% increase in comps, and Kohl's ( KSS) reported a 7.1% jump that beat expectations. For its part, Nordstrom ( JWN) was right in line with estimates with a 4.9% gain.

The teen apparel space lacked its usual flair, but those chains were facing a 15% comparison from last year. Abercrombie & Fitch ( ANF), perhaps the hottest teen fashion chain over the holiday season, said its comps dropped unexpectedly by 4%. Analysts were expecting a slight uptick, but the company was facing a comparison to the whopping 38% jump it posted in June of last year. Its shares were recently down $2.07, or 3.8%, to $51.80.

Pacific Sunwear's June same-store sales fell 2.7% from a year ago, a steeper decline than was forecast. The teen-clothing retailer also cut its second-quarter earnings guidance to 19 cents to 21 cents a share. Analysts had been forecasting 25 cents a share.

Two notable exceptions to the downtrend in the teen clothing space were American Eagle ( AEOS) and Aeropostale ( ARO). American Eagle said its June comps rose 11% from a year ago, helping it bump up second-quarter earnings guidance. It faced a 28% comp from last year.

Aeropostale recorded a gain of 5.3%, handily beating expectations for a 0.8% rise. Shares of Aeropostale were recently up 37 cents, or 1.3%, to $29.54.