When to Go
Summers are hot in the city, but when you go higher up in the Front Range the days may be warm but the nights are cool. It's a time of year when many hikers and bikers head for the higher peaks. Heavy traffic on I–70 during weekends and holidays has become a sad fact of life for those wanting to explore the Front Range and Colorado's High Country. Slowdowns peak on Friday and Sunday afternoon when stop-and-go jams are the norm, particularly around Idaho Springs and Georgetown. Winter weekend and holiday traffic fares little better, with regular slowdowns in the morning rush to the Summit County ski resorts and afternoon returns.
Many locals claim that the best times to visit Colorado are the spring "mud season" and autumn, when the tourists are gone and the trails are empty. In spring the Front Range mountains are carpeted with fresh new growth, while late September brings the shimmering gold of turning aspens. The interstate is well maintained. It's rare, but atop the mountain passes and at the Eisenhower Tunnel it's possible to see a bit of snow during the summer.