Myanmar weather in August is in the middle of the wet season which lasts from May to September. It seems like we are standing in front of a waterfall when it rains. Generally, rains happen once in the morning and once later in the afternoon. It may be dry or there may be major downpour around midday as well.
Although rainfall will start to subdue towards the end of the month, you should expect heavy rains wherever you travel in Burma. Temperature is still high as the July (averaging highs of 27 – 30°C). The beaches on the west and southern coast are still closed due to the bad weather, traveling across much of the country may be difficult, or even some places are inaccessible. Though the weather is not really in good conditions the landscape, temples, paddy fields and people are still worthwhile to pay a visit.