in Hanoi for a few days

Hey I am in Hanoi until Sunday. Doing a backback tour through Southeast Asia. I was wondering if there are any internations events. I am headed to Sapa or Hanlong Bay on Sunday. How cold might it be in Sapa now? I didnt bring much warm cloths. wanted to get them here. Does anyone recommend where I could get warm pullovers and maybe a sleeping bag here in Hanoi? Would appreciate your help :)
Sahar