Hanoi Foliage
 

What is the best time to see fall foliage in Hanoi?

Hanoi doesn't really get cold enough for leaves to turn and fall. I've been there in mid-Dec, and it's only been in the low 60's F. It gets much colder in the Highlands - the Sapa area in mid-winter can even get some rare snow.

Actually I was referring to fall colors when I mentioned "foliage". :)
So what is the best time to see that in Hanoi?

You pretty much need frost and sustained freezing temperatures to force a good number of species of "hardwood" trees to shed their leaves at the same time (chlorophyll - the green stuff which is soluble - is reabsorbed into the tree while the yellows (lignin IIRC) and reds (anthocyanins) cannot which gives you the colours). It just doesn't get (anywhere near) that cold in Hanoi. The other factor that causes trees to shed their leaves is drought but that is nowhere near as spectacular.

But clearly there are colored leaves in Hanoi, considering these photos. Not foliage?

http://khamphahanoi.info/wp-content/...locvung1_1.jpg

http://hanoi-online.net/wp-content/u...noi-autumn.jpg

I think being able to forward-guess exactly when Hanoi's leaves might be turning is impossible. It depends on what the weather patterns are doing both temperature and rain-wise. And in some years, might not really have much of a colorful presentation at all, will go from green to brown then fall quickly. I've been in Hanoi in October and November during relatively cold years, and my experience was the latter--very little color. It's not like trying to time the leaves in Vermont, which is fairly predictable.