With much of the United States baking in mid-summer heat, it’s hard to imagine that some retailers are already rolling out back-to-school promos.

Sure, Amazon.com, Inc. (NASDAQ:AMZN) acknowledges the following on its promo page: “We hate to tell you ... you're early. (Bet the students are happy!)”

But Walmart Stores, Inc. (NYSE:WMT) and Apple Inc. (NASDAQ:AAPL) are less cheeky about how early they’re rolling out their campaigns for the second-most important retail season of the year, estimated to be worth about $84 billion between elementary and primary school and college.

The so-called shopping-season creep, when companies start their seasonal promotions earlier every year, has already seen Halloween goodies showing up weeks before the Oct. 31 festivities and candy-striped Christmas tchotchkes appearing on some store shelves before Thanksgiving.

"In seven and a half years, I've never once seen so much emphasis put on back-to-school before July 4," National Retail Federation (NRF) representative Kathy Grannis told AdAge.com.

The NRF, the nation’s largest retail advocacy group, says price-conscious American consumers are gradually shifting their buying habits for the $580 billion holiday-shopping season – spacing out purchasing over several paychecks with a lull between earlier and later buys. The Internet has certainly changed the landscape – consumers are utilizing e-commerce more than ever before and that allows them to make purchases from home whenever they see deals advertised online.

Last year, Americans spent more year-over-year on both college and pre-college back-to-school spending, according to BIGinsight, and there’s no reason to expect this year will not continue the trend, considering consumer confidence is higher now than it was in recent years.

But Walmart and Apple are certainly not taking any chance to miss some early buys even as most students are still in summer-break mode. Amazon.com, J.C. Penney Company, Inc. (NYSE:JCP) and Target Corporation (NYSE:TGT) all say they’re starting their back-to-school deals at the same time they have in recent years, in late July.