Shoulder season doesn't fall at the same time everywhere, but if you time your visits right, you can see some of the world's greatest places for a fraction of the price.
SEPTEMBER
Denali National Park, Alaska
After Labor Day, foliage thins out, making it easier to view caribou, moose and bears as they live it up before winter's chill returns in October. The National Park Service stops running its shuttles mid-month, but visitors can still access many park roads by private car.
Cape Cod, Mass.
By mid-September, a timeworn cliché comes true: The coast is clear. And it's still warm enough to explore the area's sand dunes. On weekends, B&Bs don't so much drop their prices as pile on the free perks.
Southern Caribbean
Lying outside the hurricane belt, these islands (including Aruba and Bonaire) deliver tranquil weather that's only a few degrees hotter in September than during the rest of the year.
Iceland
Chilly temperatures in the upper 40s during the day don't put an end to whale-watching tours, glacier hikes and dips in hot thermal springs; the only difference from the warmer summer (other than reduced museum hours) is that large group tours are replaced with intimate outings. Weekend hotel rates in Reykjavík drop by about 15 percent.
Marrakech
In September, demand for the traditional riad (a courtyard home turned into a hotel) is below its December crest, when the Europeans swarm in. Expect hotel discounts of up to 50 percent and sunny days with an average high of 90 degrees.
Cape Town
One of the world's prettiest cities shows off its seaside views in September, a great time for whale-watching. Hotels and inns are historically only 60 percent full, prompting hoteliers to unveil deep discounts.
OCTOBER
Nova Scotia
Fall-foliage season peaks in October, later than in parts of New England. Lodging here is also a better value than in high-season Vermont, partly because of an exchange rate favorable to American visitors.
London
As leaves fall in London's parks, so do hotel prices citywide. Tourist sites are less crowded in October, so you'll have some breathing room in museums such as the Tate Modern. British Airways traditionally runs sales with fares discounted roughly one-third off summer prices. Temperatures tend to hover in the upper 50s; as always, pack a brolly in case of rain.
Greek islands
The European college kids return to their home countries by October, yet the sea retains its summer warmth. Hotels, inns and ferries generally charge 20 percent less than peak-season rates.
NOVEMBER
Colorado ski country
Most ski resorts reopen in November, but skiers generally don't arrive until the week of Christmas. To get customers onto the lifts, resorts run promotions such as free ski passes for children when parents buy their own. Tip: Breckenridge Mountain Lodge is offering starting rates of $43 a night — 43 percent off regular-season rates.
Costa Rica
The average November rainfall of six inches is half the level of September and October, but tourists haven't yet arrived in droves for winter surfing and zip lining.
Buenos Aires
The jacarandas bloom with lavender-blue flowers in November. But 23 percent fewer Americans fly to the Argentine capital this month than in December, resulting in a lower demand for tickets. Fares from New York City are about $100 cheaper now than in December.
Paris
The City of Light is always buzzing, but its convention business slows down in November. Airfares and hotel prices plunge. In 2008, the average air/hotel package price booked via Expedia for November was half the average for April. Scattered showers are typical, but much of Paris's charm is indoors, anyway — in its cafés, galleries and boutiques.
Thailand's Andaman Coast
The wet season is winding down. If you don't mind occasional showers, you'll enjoy verdant foliage and clear water for diving and snorkeling. Hotels slash their rates by about 50 percent compared with the peak winter (dry season) prices.
Beijing
International visits drop about 20 percent from their summer highs by November, and prices fall, too. Average temperatures climb into the 50s, but things stay pretty dry. Friendly Planet Travel sells an eight-night escorted-tour package with airfare for $1,199 per person this month — $400 less than in July.