Will it be cold in Halong Bay?

It can be quite cool from November to March in Halong Bay, there are some days during December and January can be very cold (about 10 DC) but this does not last very long. If you are planning to travel to Sapa during this time too then it would be good to bring along some good jackets with you!

Please see the best time to visit Halong here: http://footprint.vn/halong-travel-faqs/when-is-the-best-time-to-visit-halong