"This is obviously a very strong showing," said Scott Hoyt, senior director of consumer economics at Moody's Economy.com, "but it's very much driven by special factors."
The chain stores received a boost in March from unusually warm weather, Easter shopping and improved consumer confidence, Thomson said in its report.
Hoyt also noted bad weather in February could have contributed to pent-up demand, and March enjoyed relatively easy comparisons over the year.
"The Easter calendar shift is a huge factor, and March's gain will be at the expense of April's figures," Hoyt said. "Many retailers and analysts say you should combine the two months for a true indicator of what's going on, so we'll have to see what happens next month."
Still, March's report was welcome news for the retail industry, for which the recession has been marked by numerous store closings and the bankruptcy of entire chains such as Circuit City.
The data are also important to the overall recovery, as consumer spending fuels two-thirds of the economy. In a separate report last week, a research group's report showed consumer confidence rose in March after a sharp drop the previous month.
Higher-end women's apparel store The Limited (LTD, Fortune 500) handily beat expectations, reporting a 15% increase over the year. Thomson Reuters had predicted only a 6.8% jump.
Many teen clothing retailers also posted strong numbers. Aeropostale (ARO) had the strongest sales so far at a 19% increase, while Zumiez (ZUMZ) gained 13.2%.
But other teen apparel stores posted the biggest misses. That included the upscale Abercrombie & Fitch (ANF), which reported only a 5% increase, missing Thomson's expectation of a 6.6% rise. Alternative clothing store Hot Topic (HOTT) reported the weakest sales, down 7.5%, but that was better than the predicted 11.2% drop.
In the luxury sector, department store chain Nordstrom posted a 16.8% same-store sales increase, versus expectations for a 10.6% gain.
BJ's Wholesale (BJ, Fortune 500) reported the strongest increase among discounters, at 10.6%. Costco (COST, Fortune 500) saw a 10% jump, beating estimates of a 9.3% gain.
Tractor Supply shares up on higher 2010 earnings outlookRetail Sales
