On a historical basis, August is not the best month to be long stocks. Once upon a time, the eighth month of the year was actually the best stock market month due to the important role agriculture played in the U.S. economy.

The world’s largest economy has obviously evolved and August has, since 1987, been the worst month for the S&P 500 and Dow Jones Industrial Average, according to the Stock Trader’s Almanac. Of course, August vacation time for plenty of Americans and that includes money managers and traders. Combine August’s reputation for lethargy and the glum returns offered by stocks at this time of year and it is not surprising that low beta sectors are usually the month’s better performers.

That includes consumer staples. Last month, we noted that the materials sector finds itself in a sweet spot in July. While it was not the best-performing sector fund, the Materials Select Sector SPDR (NYSEArca: XLB) did gain 5% last month. [July Split Decision For Utilities ETFs]

Last August was something of an anomaly as the S&P 500 gained 2.6%. The Consumer Staples Select Sector SPDR (NYSEArca: XLP) was flat, but that does not mean XLP has not been a potent August play. XLP is the best August performer among the nine sector SPDRs ETFs, according to CXO Advisory. Over the 14 Augusts in which XLP has traded, the largest staples ETF by assets has posted average gains of just under 1%.

That may not sound like much, but only the Utilities Select SPDR (NYSEArca: XLU) is even close to competing with XLP for honors as the best SPDR in August. Fourteen years may not be enough a data for some investors, but using a deeper data set, it is apparent that the staples is decent in August. From 1987 through 2012, the staples sector rose 13 times in August. [Defensive Staples ETFs for Yield]

Any August strength out of XLP will be an extension of what has been a solid year-to-date performance. Buoyed by sturdy showings by holdings including Procter & Gamble (NYSE: PG), PepsiCo (NYSE: PEP), Colgate-Palmolive (NYSE: CL) and General Mills (NYSE: GIS), XLP is up 16.6% year-to-date. [Mimic Buffett With These ETFs]

Assuming XLP turns in an impressive August performance, investors may not want to be too hasty in dumping the ETF because it is the second-best SPDR behind XLU in September. XLP has risen in four of the past five Septembers.

Consumer Staples Select Sector SPDR

ETF Trends editorial team contributed to this post. Tom Lydon’s clients own shares of P&G.