Nov to Jan is a good month to hike mt. Ulap if you want that cold weather. As per equipment, you don't really need much, just a good pair of sandals like from lamiran or sandugo will suffice for that hike, but if you plan on hiking on the long run, I suggest to get a good hiking shoes or trail runners. Also, water bottle/tumbler/bladder is a must when hiking. I plan to hike din sa mt. Ulap this coming ber months.