Southeast Asia forum

"Rainy season" does not necessarily spell doom and gloom for travelling the region. In fact there are tons of people visiting June-August for European school holidays. Tropical rains don't tend to last all day - more like hot days then late-afternoon or evening quickie thundershowers. It can be worth monitoring any tropical drepressions/storms which bring unusually big rains. I usually just look at a satellite loop like this one: http://www.goes.noaa.gov/sohemi/sohemiloops/vsmtsatw.html to get an idea if any nasties are coming. Most of the time should be just fine once you're familiarised with the climate.

The driest area June-Sep is usually the lower Gulf of Thailand (islands Ko Tao, Ko Phangan, Ko Samui, and the mainland east coast) and eastern side of the Malay peninsula, but I would not be put off visiting anywhere in the region based on the possibility of rain. We get a lot of people coming up to Chiang Mai and just bring sturdy shoes and a rain poncho if you go trekking for a few days. It's a heck of a lot better than March/April which is just plain hot and too uncomfortable for heavy outdoor recreation. Rain is sometimes a good thing too.