Longs Peak Weather Forecast 4345m sgnstqcdyllxcomWeather upon Longs Summit may be unpredictable. The weather on Longs Summit could vary significantly. It is important to monitor the weather forecast and be prepared for any kind of climate conditions hiking on Longs Peak. The mountain is famous for its abrupt climate changes as well as risky weather events. Dressing in multiple layers and bringing extra gear like rain jackets, caps, and mittens is critical to stay safe from the elements.