Chang Mai is already cleaning up the flooding it had (it was almost a week ago so probably all gone).
Bangkok: it's not like the entire city is flooded. It's not like every tourist spot, hotel and attraction is underwater. Bits of the city are experiencing flooding, but it seems that the barriers have done their job and held most of the water out.
As a tourist you're unlikely to experience anything but some inconvenience. It's a different matter for the Thais, especially those to the north of Bangkok and outside the flood barriers. It's a full scale disaster for many thousands of them, it's had a devastating impact on their economy and it will take some individual families many years to recover.
October is the usual month for flooding in bangkok, it's usually gone by mid November. This year has been particularly bad, and north of Bangkok it may still be a problem till mid December - but in Chang Mai and Bangkok, I don't think you'll even notice anything by mid November. about 8 years ago
The last answer is 100 percent correct,trek up to local tribes bring lots of candy for the kids and some cigs for the elders, and have nobody take you to see the golden triangle where they grow the ploys it's a great exp don't take a tour but do it alone just hire a driver for the day very cheap,,,enjoy about 8 years ago