At a Glance
- Avg High: ~74°F
- Avg Low: ~44°F
- Water Temp: Warmest
- Kokanee Salmon: Early run begins
August in Grand Lake
August is Grand Lake's warmest month and in many ways its fullest summer experience. Water temperatures on Grand Lake and Shadow Mountain Lake reach their highest point, making swimming and paddleboarding most comfortable. The hiking season is at full peak — every trail in RMNP is open and accessible.
Late August marks the beginning of the kokanee salmon run — kokanee, a landlocked salmon, begin their pre-spawn movement through Grand Lake and Shadow Mountain Lake. Anglers from across Colorado target kokanee in late August and September, making it one of the most productive fishing periods of the year.
August Activities
All summer activities are at full availability in August — kayaking, paddleboarding, fishing, hiking, and wildlife watching. The Grand Lake Marina is fully stocked with rental equipment. RMNP timed entry permits for the Bear Lake Road corridor are required in August and should be reserved on recreation.gov weeks or months in advance.
Late August afternoons can produce dramatic thunderstorms over the mountains — these are typically fast-moving and clear by evening. The light in late August — golden afternoon sun, clearer air than July — is among the finest of the summer for photography and lakeside evenings on the deck.
August Booking Notes
August is booked as far in advance as July. Last-minute August availability at Grand Lake Cabins is rare. If August is your target, book 3 to 6 months ahead for the best selection of properties and dates.
Book direct at cabins-grandlake.com to avoid platform fees on peak summer stays. A 7-night August stay saved from Airbnb fees can amount to $300 to $500 depending on the property.