When I was in Vietnam 5 years ago, I did a two night boat trip in Halong Bay, which I really enjoyed. It was June or July so the weather was hot and I remember swimming in the bay at night where there was some kind of algae that looked like tiny stars when you swam through it. My husband and I are thinking of making Hanoi a destination for a trip in early 2008 (most likely January or Feb.). Do you think it would be too cold to visit Halong Bay overnight? I would love to stay on a boat, but I'm concerned that it wouldn't be a great experience because the weather would be too cold.

Did a daytime junk cruise in early March. I was FREEZING!!!

We were there for day cruise in last week December...very nice weather, pleasant, not for swimming, but no sweaters.

Just did the Halong Bay for a night in January (near the end)..it was quite chilly!!!!!

hi
Yes, too cold you can overnight on boat trip and enjoy the view of Halong Bay but can not swim.

I did a sea kayaking trip there over Christmas time. We stayed in bungalows at night. It wasn't tropical type condtions, but it certainly wasn't cold. But if you want a good warm sunny tropical beach experience, head further south.