(Reuters) - Several large retailers, including Target Corp (>> Target Corporation), Macy's Inc (>> Macy's, Inc.) and Gap Inc (>> The Gap Inc.), missed sales estimates for April, in sync with broader economic indicators and as cooler weather chilled some of the enthusiasm shoppers had shown earlier this year.

An earlier Easter also hurt April sales by shifting demand into March.

Of the 20 retailers tracked by Thomson Reuters, nine missed Wall Street estimates of April sales at stores open at least a year.

The Thomson Reuters same-store sales index showed a rise of 0.8 percent, short of analysts' estimates for an increase of 1.5 percent. Sales in March had risen 4.3 percent.

"The past few months have all been exaggerated," said Kit Yarrow, a consumer psychologist and professor at the Golden Gate University.

"Many seem to be looking for the magic moment when the recession is fully behind us. That just won't happen ... it's like being on a diet and checking the scale every morning."

Retail Metrics analyst Ken Perkins said about one-third of the cooling in sales was a result of broader economic conditions, adding that May will be a better gauge for consumer spending, because April sales also saw a big pull back from the Easter shift.

In April, the S&P 500 posted its first monthly decline since November on signs that the economy may be slowing and as a recession in Spain highlighted risks in the euro zone.

"While a majority of chains missed expectations this month ... the earnings guidance coming out retailers was quite positive," he said.

Clothing retailers, including Gap and Aeropostale Inc (>> Aeropostale, Inc.), said their earnings in the just-ended fiscal first quarter should come in above analysts' expectations as they were able to rein in discounts and keep inventory under control.

"It is possible to increase profit and margins sometimes at the expense of sales, and that is not always visible in monthly sales numbers," said Joel Bines, managing director of AlixPartners' retail practice.

TJX Cos Inc (>> The TJX Companies, Inc.), operator of the T.J. Maxx and Marshalls low-price chains, also raised its profit estimate after doing so in April.

The Standard & Poor's Retail Index <.RLX> fell 1.2 percent in afternoon trading, while the broad S&P 500 stock index <.SPX> was down nearly 1 percent. Shares of Zumiez (>> Zumiez Inc.), whose 10.1 percent gain topped all other chains, were up 1.02 percent.

THE CALENDAR EFFECT

Many industry experts like to look at March and April sales in combination, to account for the calendar shifts.

March results benefited because of an early Easter -- April 8 this year, compared with April 24 in 2011. It was also the warmest March in more than 50 years, which helped spur sales of spring clothing.

Combined, March and April same-store sales were up 4.6 percent, excluding drugstores, said Michael Niemira.

That increase was "a little bit on the softer side relative to the year-to-date trend, but not dramatically so," he said.

For May, the ICSC expects same-store sales to increase 4 percent to 5 percent.

HITS AND MISSES

Macy's April same-store sales rose 1.2 percent, below the 1.9 percent increase analysts were expecting. The department store chain blamed the earlier Easter and later Mother's Day for the slower growth.

Target posted a 1.1 percent rise, missing the analysts' average forecast of 2.8 percent. The discount chain said an increase in the average transaction's value had offset a slight decline in the number of comparable-store transactions.

Gap's same-store sales fell 2 percent, which was worse than the 0.8 percent drop analysts were expecting.

Still, the company gave a quarterly earnings outlook above Wall Street estimates, as did Aeropostale Inc (>> Aeropostale, Inc.) and American Eagle Outfitters Inc (>> American Eagle Outfitters).

Apparel retailers have finally started selling closer to full price after years of discounting. Bines said that while tempered discounting may have hurt Gap's April sales, it helped margins.

Victoria's Secret parent Limited Brands Inc (>> Limited Brands, Inc.) posted a 6 percent rise in same-store sales, beating estimates.

One big disappointment was Costco Wholesale Corp (>> Costco Wholesale Corporation). The company missed Wall Street estimates for the second month in a row, suggesting competition with other big-box retailers hurt the biggest warehouse club operator's performance.

Its same-store sales rose 4 percent, while analysts were expecting a 5.1 percent increase.

Costco, which competes with Wal-Mart Stores Inc's (>> Wal-Mart Stores, Inc.) Sam's Club and BJ's Wholesale, has been "a bit more aggressive in terms of price to drive traffic," said Brian Sozzi, chief equities analyst of NBG Productions.

(Reporting by Nivedita Bhattacharjee and Jessica Wohl in Chicago, Phil Wahba in New York; Editing by Lisa Von Ahn and Maureen Bavdek)

By Nivedita Bhattacharjee