There's a persistent myth that the closer you are to checking in, the lower rates will go because hotels are anxious to fill unused rooms, McInerney says.
In reality, hotels use sophisticated formulas to adjust pricing, and there could be a better rate one month out if room reservations haven't hit their target for that time frame.
But McInerney also says reservations can be low right up to the evening of a particular day. That's why many travelers who don't insist on staying at a particular hotel chain use smartphone apps that search for the best last-minute hotel deals.
Two popular last-minute-rate apps are Travelzoo and Hotel Tonight, says Christodoulidou. In lieu of apps, the best way to look for last-minute deals is to shop an opaque site like Priceline.com or a travel comparison "meta" site like Kayak.com, she says.
On short notice, the old strategy of calling the front desk clerk and asking for a deal still may be viable with some hotels, Mandelbaum says.