Christmas - March; June - August
During the height of winter, Aspen is at its busiest. This is especially the case during the Christmas-New Year holiday week when vacancies are few, top-tier lodging prices go astronomical and reservations must be secured months in advance. Other than Christmas, President's Day week, and late January, when Aspen hosts ESPN's Winter X games, choice rooms can usually be found with a few weeks notice. Early- through mid-January offers good snow and less-crowded slopes. February through early-March is busier with kids on spring break. Winter highs average in the 30s and lows dip toward single digits, but this is Colorado. Weather gods here can fling anything at you from sunny warmth to bitter cold any time of the season. Summers in Aspen can be just as crowded and almost as expensive as winters. While rooms may be secured on short notice, reservations a week or two in advance are advised, especially around Independence Day. Summer temperatures tend to be quite pleasant, with highs in the 70s and lows in the 40s. Blue-sky mornings and afternoon thunderstorms are common. While shorts and T-shirts are appropriate daywear, a sweater or light jacket may be needed after dark.
Mid-April - Memorial Day; mid-October - Thanksgiving
Locals call these two time periods "mud seasons." In the spring, the ski areas close, and melting snow leaves hillsides slushy. The town seemingly dies, with store owners and top chefs often escaping on end-of-season, sanity-retrieving vacations. The town-emptying phenomena repeats itself in late autumn after the leaves have fallen and early snowfalls once again turn hillsides slushy. For those who want to taste caviar luxury at meat-and-potato prices, spring or fall mud seasons offers an ideal time to visit Aspen. Lodging rates in top hotels drop to about a third what they are during the height of winter. Restaurant reservations are seldom needed, and merchant closeout sales abound. It may not be the prettiest time of year and the weather may be cold and blustery, but mud season provides a rare opportunity to sample the best for less.
Late-March - early-April; September - mid-October; Thanksgiving - Christmas
Aspen sports three distinct "shoulder seasons." The final weeks before the lifts close provide an ideal time to go skiing. Crowds are miniscule, slopes are often at their deepest, temperatures tend to be warm, the snow soft and mushy, and bargains abound. Lodging can go for half what it would be at season's max.A decade or two ago, lodging rates immediately plunged to low-season levels right after Labor Day, but this is not the case anymore. Hotel owners discovered that hillsides gilded with the mustard-yellow leaves of autumn-tinged trees bring in enough leaf-peepers to fill their beds. Still, it's a great time to visit. The town isn’t crowded, the weather is typically temperate and lodging deals can sometimes be found on short notice. Best of all, the hillsides shimmer at their Midas-touched best. Pre-Christmas skiing days provide a final shoulder season. Lifts typically open Thanksgiving Day with a few runs covered by largely hose-blown snow. Lodging can be cheap and lift tickets go at a discount, which is good. The bad is that with little terrain open, side-winding beginners must share trails with Kamikaze straight-liners. Like minivans in a NASCAR race, the dichotomy can lead to unpleasant confrontations.