Mountain ecosystems can vary dramatically depending on the season and Rocky Mountain National Park is no exception. From deep winter snows to sunny alpine meadows, this park transforms with the calendar. While there’s drawbacks to visiting in each season, we recommend heading to the park in summer, fall or winter. Skip spring, unless you enjoy postholing through spring snow or hiking on muddy trails.
Here’s the pros and cons to visiting in every season.
Spring (April through mid-June)
Spring in Colorado’s mountains is referred to by locals as “mud season,” and not in an affectionate way. Weather this time of year is unpredictable. Some days, especially at lower elevations, might be warm and dry while the next sees a big spring snowstorm. Average spring highs vary from the 50s and 60s in Estes Park, to 40s and 50s at Bear Lake. In early spring, snowy trails can be miserable even on snowshoes as the rapidly melting snow causes you to sink down with each step. Later in the year, the warm spring sun melts snowpack during the day, turning the trails into mud. At night, temperatures often get cold enough to solidify the trails again so you might start out in the morning on hard packed paths but end up wallowing in mud by 10 a.m. The higher in elevation you go, the more likely you are to encounter still-deep snow.
Trail Ridge Road remains closed through late-May, making accessing both sides of the park difficult. Even after its opening date, you will likely encounter snow in the high alpine through early July.
We don’t recommend it, but if you do choose to visit the park in spring, stick to lower elevations where the weather is likely to be warmer and drier. Bring traction devices you can slip on your shoes if the trails start to get muddy, along with trekking poles to keep your balance. Always check the weather forecast and park trail conditions (www.nps.gov/romo/planyourvisit/trail_conditions.htm) before setting off.
Wondering if the trails you want to hike are currently covered in snow? Download GAIA GPS to see real-time data: www.gaiagps.com.
Summer (mid-June through August)
As far as climate goes, summer is one of the best times of year to visit the park. Since all of Rocky Mountain is above 7,500 feet, temperatures remain pleasant, even in the hottest parks of the year. Low elevations see highs in the 70s and 80s while higher elevations remain in the 60s and 70s. Trail Ridge Road is open, allowing easy access to both the east and west sides of the park. The short window when alpine trails like Chasm Lake and the Ute Trail are snow-free is spectacular, with abundant wildflowers and gushing streams and waterfalls.
Summer weather is beautiful most mornings in July and August, but afternoon thunderstorms are the norm and pose a real risk to hikers, especially above timberline. Aim to be back to the parking lot by mid-day and if you see dark and building clouds, turn around immediately. In recent years wildfires have become more common across the West, so you may encounter haze or smoke while hiking in the park, especially in late summer. If you are sensitive to smoke, it’s worth checking the air quality forecast before heading out (www.iqair.com/us/usa/colorado/estes-park).
Rocky Mountain’s gorgeous summer weather isn’t a secret, though. As the fourth most visited park in the U.S. in 2022, the crowds can be intense. Timed-entry reservations are required from May 26 to October 22, 2023 and many parking lots fill up extremely early in the morning, forcing visitors to take the park’s free shuttle system from Estes Park or the Bear Lake Park and Ride. July is historically the park’s busiest month, followed by August. If you choose to visit in the summer, you definitely won’t be alone.
Fall (September through October)
Autumn is one of the best times of year to visit Rocky Mountain National Park. Summer heat and thunderstorms give way to cool and beautiful fall weather. September, especially, is a great month to visit the park with average highs in the 60s. The park’s aspens begin to turn yellow in late September and snows usually hold off until mid-October, making for gorgeous hiking weather. Unexpected early snows can occur, so always check the weather forecast before setting out, especially on high elevation trails.
Fall is also one of the best times to spot wildlife in the park. Mid-September through mid-October, elk gather on the park’s east side in a display known as “the rut.” Haunting bugles can be heard throughout the area and you may spot bull elk tussling over females in this mating ritual. Be sure to give park wildlife a wide berth, especially this time of year.
While not quite as busy as mid-summer, September still sees high visitation numbers, especially on the eastern side of the park to see fall colors and spot elk. Timed-entry permits are required through October 22, 2023 and you’ll likely still need to take the park shuttle buses to trailheads unless you arrive very early. Trail Ridge Road usually closes mid-October.
Winter (November through March)
When the snow starts to fall, the park transforms into a magical winter wonderland and sees a fraction of the crowds. It’s one of the best times of year to visit. While November and early December can mimic spring conditions, with warm and muddy days, by January most of the park is covered in a blanket of snow. Strap on snowshoes and hike to Emerald Lake where you can walk across several frozen lakes along the way. Sledding in Hidden Valley and cross-country skiing on the park’s west side are other great winter activities.
Popular parking lots like Bear Lake and Glacier Gorge can still fill up early, especially on weekends. Shuttles don’t run in the winter months, so plan to arrive early to make sure you get a parking spot.
The main drawback to visiting in winter is unpredictable weather. Storms can move in quickly, turning a bluebird day into a blizzard. Winds can be relentless and snow can get unexpectedly deep. Getting out on the trails requires a bit more preparation in the snow. Be prepared, with warm, waterproof and windproof layers, as well as snowshoes in case you encounter deep snow. Avalanche conditions are important to be aware of as well, especially when traveling above treeline. Check the forecast before heading out (avalanche.state.co.us).