Aspen is a world-class ski resort in an area with an arid climate. That means fluffy powder in the winter, warm days and cool nights in the summer, and 300 days of sunshine. Ski season begins on Thanksgiving and runs through mid-April. For the best deal on a ski vacation package, book your trip for early December or April. The epic powder days come in late February and March. Summer season kicks off in mid-June, when the town is bustling with activities and festivals, and starts winding down in September. Late July is a beautiful time to see the wildflowers in full bloom, and in September the mesmerizing foliage on brilliant yellow groves of aspen trees covers the hillsides. May, October, and November are considered the mud months, when many stores and restaurants close down and locals go on vacation. Even though not as vivacious as in summer or winter, Aspen is still a wonderful experience in these months—and they are definitely the cheapest times of year to visit.