Rock Climbing in The Diamond RMNP Rock Mountain ProjectClimate on Longs Peak is capricious. The at the summit of Longs Peak may fluctuate drastically. It's essential to monitor the weather forecast and be ready for any kind of climate conditions before Longs Summit. The mountain is renowned for its abrupt weather changes as well as risky storms. Wearing the right clothes in multiple layers and bringing extra gear like precipitation jackets, caps, and gloves is essential to be protected from inclement weather.