More than three million travelers visit Rocky Mountain National Park each year. High season is summer, when the weather is good and the snow has melted—and the traffic is heavy. If you can, traveling in the months of May, August, September, or October will help you avoid the masses.
Rocky Mountain National Park and Trail Ridge Road are open to vehicles from Memorial Day weekend through mid-October. Although snow is possible year-round, the National Park Service closes Trail Ridge Road between Many Parks Curve and the Colorado River Trailhead during the wintriest months (December to March), when the park is often slammed with arctic conditions. Snowfall is also common in April and May, and again from September to October, which means RMNP roads may be closed. To see the park in winter, explore by snowshoes or cross-country skis, but exercise caution and safety and be sure to check for official closings.
Any time of the year, be prepared for windy conditions and temperatures at least 20 to 30 degrees cooler than Estes Park or Grand Lake, with averages ranging from below zero to the high 80s. Higher elevations can get extreme conditions year-round, including spring storms and winter blizzards, and snow in July is not unusual. For safety, always pack a warm jacket, gloves, and a blanket for your car.