Rock Climbing in The Diamond RMNP Rock Mountain ProjectClimate on Longs Mountain may be fickle. Conditions at the summit of Longs Mountain can change drastically. It can be essential to keep an eye on the forecast and be equipped for any kind of climate conditions hiking on Longs Mountain. The peak is known for its abrupt weather changes and risky storms. Choosing the suitable attire in multiple layers and bringing additional gear like rain coats, caps, and mittens is crucial to be sheltered against inclement weather.