About Rocky Mountain Weather
Rocky Mountain National Park has two distinct climates. The Continental Divide runs northwest to southeast through the center of the park. This accounts for the two climate patterns - dry on the east side near Estes Park and more humid with twice the precipitation on the west side near Grand Lake. Temperatures are moderate at the lowest elevations, but quickly become much colder as elevation increases. The top of Trail Ridge Road, at over 12,000 feet, is likely to be cold any time of year, and may see snow at any time. It may be 20°F cooler at this altitude than the lower parts of the park. The statistics below are taken from the town of Estes Park, and are representative of the conditions on the park's lower east side, which includes areas such as Moraine Park, Glacier Basin, and Bear Lake.
Visitation Seasons
The spring is a time of uncertain weather and light crowds. Heavy snows of the winter are changing to rains, with either possible at any time. Trail Ridge Road usually opens fully on Memorial Day weekend. Most trails remain snow-covered until late in the spring.
The summer is the high season in the park, with warm weather and huge crowds. Most trails are snow-free, park roads are open, with Old Fall River Road typically being the last to open in early July. Campgrounds and lodgings are usually full, and rates get quite high.
The fall is probably the best time to visit the park. The crowds start to dissipate, and September brings both the elk mating season and the changing of the aspen leaves to golden colors. Lodging rates are lower, and finding a campsite is slightly easier, although reservations are still suggested. Snow starts to be more common towards the end of September, and Trail Ridge Road may close periodically before its closure for the season, usually sometime in October.
The winter is a time of quiet in the park, although snow hiking, especially along
Bear Lake Road trails, is fairly popular. Snows keep the higher portions of Trail Ridge Road closed throughout the winter.
