Longs Peak Weather Conditions and Forecast Climate on Longs Summit can be volatile. The weather on Longs Summit can change greatly. It can be essential to check the weather forecast and be equipped for any kind of climate conditions ascending Longs Summit. The mountain is renowned for its unexpected climate variations and hazardous storms. Choosing the suitable attire in layers and bringing spare equipment like rain coats, hats, and gloves is essential to stay safe from inclement weather.