like others say it depends where abouts in the country you will be.

i hear ko samet has the driest climate in the whole of thailand (rayong province) less than 2 hours from bangkok

and ranong province on the west coast near burma has the wettest climate in the whole of thailand.

i would say avoid andaman side (west coast) phuket,phi phi,krabi,trang etc between may-october/november)

avoid bangkok may-november (i was there in august/september and it rained everyday almost allday without fail,flooded streets everyday guranteed )

avoid east coast (gulf of thailand,islands ko samui phangan,tao etc) between october/november - january/february

as for the north of thailand im unfamiliar with so cant comment personally,although this site has some very useful information with regards to weather forecasts and patterns.

Thai Meteorological Department

chohkdee

sorry dont agree with the avoid Phuket from May - Oct/Nov - have been in may june july aug sept oct nov dec etc etc and never been dissapointed -it depends on what you are looking for not everyone wants a major suntan - and lets face it unless you spend 5 years there you are not getting one

i usually travel mar/apr/may, a 10 week break, unless a thought actually enters my brain, usually a slow ride to phuket and back from udon thani, NE Thailand. of course rainy season hasn't or is about to kick in, so things are a bit dry/dusty/ugly, and lakes/rivers/especially waterfalls may be low to non existent, but clear as opposed to brown.

the north does their burn off of farming area, which makes for visibility problems, health problems if susceptible. but usually spend most of my time between kanchanaburie/bkk/points south, so a bit greener.

the other time i holiday is sept/oct, with sept winding down rainy season, oct usually dry, but plenty of green and if into waterfalls / trekking and such, most places should still be very lush. only get 3 weeks during this period, so unless doing something fairly local, it's again, cruise down to phuket, kata beach for me.

prefer these times, as being a cheap charlie / thrifty holidayer, it's not as crowded and rates start dropping considerably, weather is still good on both ends, as in 9 yrs, only been rained out once for a week in may, so pretty lucky in that respect.

don't let rainy season scare you too much, unless you only have a week or 2, then i might be a consideration, but on a bad day, i usually rains heavy overnight, then maybe a afternoon quick downpour. sometimes a week with nothing, and the opposite, week of constant rain. luck of the draw.

But Bangkok, Chaing Mai, Phuket and Ko Samui

where to go, personal choice obviously, i'm happy to arrive in bkk, but happy to leave, though can always find something new and different, but it is a big city, with all the negatives. not a fan of CM or Samui, just personal choice, no extreme negatives and enjoyed my time in both, just prefer different and for me better.

enjoy.

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like you say it depends what your looking for?

if its cloud and rain and a sea that you cant swim in then by all means follow this posters advice.

and nov/dec should be ok anyway,i was refering to early november,and i didnt even mention december for bad weather with regards to phuket.

and your right not everyone wants a major suntan but when you travel over 6000 miles and a near 12 hour plane journey a bit of sun and sea time doesnt go amiss.

i may have been very unlucky but like i said in my previous post when ive visited in august/september it rained HEAVY,ALLLDAY,EVERYDAY,not short sharp showers as others say.

showers i can handle,constant rain is not my idea of fun.

anyway wherever and whatever time of year you go,enjoy

I did not mention Dec in direct answer but as in when I have visited and I have never ever been dissapointed - but then again I am easily pleased - because whatever time of year the weather is infinitley better than the UK