This is largely due to Christmas and New Year holiday that most of you will have. Although the weather is cold, this is a really wonderful time for travelers to visit Halong Bay. Consider bringing a cardigan and a jacket with you, just in case some of those chilly December days turn up while you’re there. Pack swimsuit and sun cream! Even if the air feels cool, the sun is still very strong and it’s easy to get skin burned if you aren’t careful. Find our halong bay weather and when is best time to visit halong bay ? We also recommend bringing a jumper or light rain jacket in case a shower blows through when you go on halong bay overnight cruise trip.