we plan to hike taiwan snow mountain ( 2nd highest ) in May 2019. Pls advice weather & what to wear.

I have never hike at such high altitude ( above 3,000m) and such cold mountain. Would greatly appreciate your advice on the temperature, rain and cold wind in Mid May ( our hiking trip ) and what to wear and what food Taiwan people at the camp normally eat to keep warm.
I came from Malaysia, a tropical country. Advice needed so that I don't under pack what is needed. Thanks.