I am glad I bought my Northface waterproof outer jacket and the fact that I wore 3 layers underneath. I also had gloves (not waterproof), and an extra pair of socks. I could have hiked all the way up to trailhead with just 2 light layers and I am so glad I bought the extra layer just in case of the scenario that happened. There were folks going up in shorts as well as those who has no rain coat or waterproof tops.
Yes, DO NOT UNDERESTIMATE THE MOUNTAIN. Prepare for the worst as anything can happen.
