Hi All, I’m looking at booking a trip that includes Vientiane, Bangkok, Siem Reap, Phnom Penh and Ho Chi Min. This is from mid April till mid May. My aim is to push it back and longer till the end of May but I am really worried about the weather.
Im fine with rain, appreciate its torrential, but flooding is the concern. Are any of these places ever/likely to be flooded in May? Want to get a bus from Vientiane to Bangkok, could that cause a problem?
Any help is appreciated, Thank You so much.
Josh

May can be tricky in that part of the world! weatherspark.com is an excellent source for climate data; I strongly recommend that you consult it.

IME it will certainly be a lot wetter in all of those places at the end of May than the beginning as you would be heading into the rainy season proper. Weather sites cn only use the past to try and predict the future but take no account of our changing climate patterns. When visiting for a short time you may be lucky, maybe not but periods of heavy rain are usually short lived and followed by some blue skies.

Flooding is not predictable but does happen. We have been flooded out in various places in SE Asia and it is not pleasant, sometimes for reason you may not immediately consider. I would say it is unlikely to be a big issue in May. The advantage of traveling at that time of year is that there are fewer crowds, especially at popular places like Angkor

i wouldn’t worry too much re the bus ride between Vientiane and Bangkok, but flying would be easier and unless you plan on stopping along the way, there would seem little point. Vientiane is probably my least favourite city in Asia and I just wouldn’t bother but that’s just my subjective view.

Flooding should not be a big problem in May. It's in rainy season, but the heavy rains mostly occur later in the year (September, October). You could also take the bus from Vientiane to Udon Thani in Northern Thailand and then fly to Bangkok with Air Asia.