At a Glance
- Avg High: 75°F / 24°C
- Avg Low: 49°F / 9°C
- All Trails: Open
- All Passes: Open
- Wildflowers: Late season
- Crowds: High — book in advance
The Full San Juan Experience
August in the San Juans is the gold standard of accessible high-country adventure. Every road is open, every trail is dry, and the weather — while still bringing afternoon thunderstorms — is warm and forgiving by mountain standards. Ouray sits at 7,760 feet, which means even August highs are comfortable: rarely above the mid-70s, with nights cooling to the low 50s.
Hiking options range from the easy Lower Cascade Falls walk to full summit attempts on 14ers like Uncompahgre Peak. The 4WD network opens the entire San Juan backcountry to vehicles with appropriate clearance. Fly fishing on the Uncompahgre River is productive through August as water temperatures remain cold.
Late Summer in the San Juans
By mid-August, the wildflower peak has passed at the highest elevations, but the landscape is still lush and green at mid-elevations. The light changes perceptibly through August — getting a little warmer and lower each day, which makes photography increasingly rewarding as the month progresses.
Aspen trees in the San Juans begin their color change in early September, but by late August the first hints appear at the highest elevations. If your trip straddles August and September, you catch the summer's final days and autumn's first colors — a combination that many repeat visitors specifically target.