You may find yourself in shirtsleeves on a February day, but bundling up after dark. Summer is the most popular time for visitors because of pleasant weather and Rockies baseball games, and because Denver is a natural gateway to Rocky Mountain National Park and other popular scenic and sports destinations. Because of Denver's dry climate, hot doesn't mean steamy and cold doesn't mean bone-chilling. In fact, one of the main things visitors need to remember is to drink plenty of water to avoid dehydration. Denver has a reputation for being very cold and snowy in winter, but in fact, snow rarely lingers in the city and arctic cold is also uncommon.
Winter days are usually balmy and sunny, with temperatures dropping after the sun sets.
If you're traveling to Denver from October through April, bring warm clothes. If you'll be outdoors in the mountains, pack layers of long underwear, an insulating mid-layer of fleece or wool, and a windproof outer garment that is windproof. Denver's cultural scene is most active during the winter season, and January also brings tens of thousands of exhibitors and visitors to the National Western Stock Show. The mountain resorts also draw people to Colorado in winter. Keystone and Loveland generally have limited operations in mid-October, and most ski areas are open by Thanksgiving.