September is a month of change as the monsoon begins to weaken and more settled conditions should start to develop in the centre of the country especially towards the end of the month. Temperatures remain in the high 20s°C and if you time it right this can be a wonderful time to see Myanmar, with fewer visitors and lush green landscapes.
River cruising on the Irrawaddy from Mandalay to Bagan is ideal at this time of year as you’re travelling within the dry zone whilst river levels are high. However beaches remain closed and the hills will tend to cling on to the last of the rains.